Previous Year Paper

DSSSB TGT Natural Science (Male) 7 Sep 2021 Shift 3 (Previous Year Paper)

Held in 2021

200 questions120 minutes
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General Ability (20 questions)

Question 1

Find the wrong term in the letter-cluster series given below:

WNGR, CKMO, IHSL, OEYJ, UBEF

  1. AOption (a)

    CKMO

  2. BOption (b)

    IHSL

  3. COption (c)

    OEYJ

  4. DOption (d)

    UBEF

View answer & explanation

Correct answer

Answer: (c)C.

OEYJ

Why this answer is correct

The logic follows here is:

Clearly, the wrong term is 'OEYJ'.

Hence, the correct answer is "OEYJ".

Question 2

Find the missing term in the following letter-cluster series given below:

FLC21, JPG33, ?, RXO57, VBS69

  1. AOption (a)

    NTK41

  2. BOption (b)

    NTL42

  3. COption (c)

    NTK45

  4. DOption (d)

    NTM44

View answer & explanation

Correct answer

Answer: (c)C.

NTK45

Why this answer is correct

The logic follows here is:

Hence, the correct answer is "NTK45".

Question 3

Select the related word/ letters/ number from the given alternatives.

NaCl ∶ Salt ∶∶ H2SO4 ∶ ?

  1. AOption (a)

    Acid

  2. BOption (b)

    Base

  3. COption (c)

    Sugar

  4. DOption (d)

    Water

View answer & explanation

Correct answer

Answer: (a)A.

Acid

Why this answer is correct

The logic follows here is:

  • NaCl ∶ Salt

→ NaCl is the chemical formula of Salt.

Similarly,

  • H2SO4 ∶ ?

→ H2SO4 is the chemical formula of Acid.

Hence, the correct answer is "Acid".

Question 4

Select the related numbers from the given alternatives.

LHD ∶ 321 ∶∶ XTP ∶ ?

  1. AOption (a)

    123

  2. BOption (b)

    132

  3. COption (c)

    654

  4. DOption (d)

    531

View answer & explanation

Correct answer

Answer: (c)C.

654

Why this answer is correct

The logic follows here is:​

The positional value of the letter is divided by 4.

  • LHD ∶ 321

Similarly,

  • XTP ∶ ?

Hence, the correct answer is "654".

Question 5

If in a certain language, SQUABBLE is coded as "76521138". How is 'EQUAL' coded in that code?

  1. AOption (a)

    26523

  2. BOption (b)

    86523

  3. COption (c)

    76522

  4. DOption (d)

    56523

View answer & explanation

Correct answer

Answer: (b)B.

86523

Why this answer is correct

The logic follows here is:

  • SQUABBLE is coded as "76521138"

Similarly,

  • 'EQUAL' will be coded as:

Hence, the correct answer is "86523".

Question 6

In a row of children facing north, Rajat is fifteenth from the left. Aman who is thirty from the right end is fourth to the right of Rajat. How many children are there in the row?

  1. AOption (a)

    50

  2. BOption (b)

    49

  3. COption (c)

    48

  4. DOption (d)

    47

View answer & explanation

Correct answer

Answer: (c)C.

48

Why this answer is correct

As per the given information: 

In a row of children facing north, Rajat is fifteenth from the left. Aman who is thirty from the right end is fourth to the right of Rajat.

So, the rank of Aman from left will be '19'.

Now,

Total children in the row = Position of Aman from left + Position of Aman from right - 1

= 19 + 30 - 1

= 49 - 1

= 48

Thus, the total number of children in the row is '48'.

Hence, the correct answer is "48".

Question 7

Chintu, Pintu, Suresh, Ramesh and Mahesh are five friends in a class. Each of them likes a different subject viz. Hindi, English, Maths, Science and Arts, but not necessarily in the same order. Each of them study in a different class viz. I, II, III, IV, and V, but not necessarily in the same order. Pintu studies in class I and likes Mathematics subject. The one who likes English subject and studies in class V. Chintu does not like Science or English subject. Ramesh likes Arts subject and studies neither class I nor class II. Mahesh studies in class IV.

Which is Suresh's favorite subject?

  1. AOption (a)

    Science

  2. BOption (b)

    English

  3. COption (c)

    Hindi

  4. DOption (d)

    Science or Hindi

View answer & explanation

Correct answer

Answer: (b)B.

English

Why this answer is correct

As per the given information:

Chintu, Pintu, Suresh, Ramesh and Mahesh are five friends in a class. Each of them likes a different subject viz. Hindi, English, Maths, Science and Arts, but not necessarily in the same order. Each of them study in a different class viz. I, II, III, IV, and V, but not necessarily in the same order.

  • Pintu studies in class I and likes Mathematics subject.
  • The one who likes English subject and studies in class V.
  • Mahesh studies in class IV.
ClassSubjectPerson
MathematicsPintu
I
II
III
IVMahesh
VEnglish

 

  • Ramesh likes Arts subject and studies neither class I nor class II.
  • ​Chintu does not like Science or English subject.
ClassSubjectPerson
MathematicsPintu
I
IIHindiChintu
IIIArtsRamesh
IVScienceMahesh
VEnglishSuresh

 

Clearly, Suresh's favorite subject is 'English'.

Hence, the correct answer is "English".

Question 8

Two statements are followed by two conclusions numbered I and II. You have to consider these statements to be true, even if they seem to be at variance with commonly known facts. Decide which of the given conclusions logically follow/s from the given statement.

Statement:

Some board are notice.

All notice are rings.

Conclusions:

(I) Some notice are board.

(II) No ring is board.

  1. AOption (a)

    Only I follow

  2. BOption (b)

    Only II follows

  3. COption (c)

    Both I and II follow

  4. DOption (d)

    Neither I nor II follows

View answer & explanation

Correct answer

Answer: (a)A.

Only I follow

Why this answer is correct

Statement:

Some board are notice.

All notice are rings.

The least possible diagram for the given statements is as follows:

Conclusions:

(I) Some notice are board.→ True (Because 'Some board are notice', so 'some notice are board is definitely true)

(II) No ring is board.→ False (Because 'All notice are rings' and 'Some board are notice' thus no ring is board is definitely false)

Hence, the correct answer is " only I follows".

Question 9

Three statements are followed by two conclusions numbered I and II. You have to consider these statements to be true, even if they seem to be at variance with commonly known facts. Decide which of the given conclusions logically follow/s from the given statement.

Statement:

All kitchen are hall.

Some hall are hotel.

All hotel are guest.

Conclusions:

(I) All hall are guest.

(II) Some kitchen are hotel.

  1. AOption (a)

    Only I follow

  2. BOption (b)

    Only II follows

  3. COption (c)

    Both I and II follow

  4. DOption (d)

    Neither I nor II follows

View answer & explanation

Correct answer

Answer: (d)D.

Neither I nor II follows

Why this answer is correct

Statement:

All kitchen are hall.

Some hall are hotel.

All hotel are guest.

The least possible diagram for the given statements is as follows:

Conclusions:

(I) All hall are guest..→ False (Because 'All hotel are guest' and 'Some hall are hotel', so it is possible but not definite)

(II) Some kitchen are hotel.→ False (Because there is no direct relation between 'kitchen' and 'hotel', so it is possible but not definite)

Hence, the correct answer is "Neither I nor II follows".

Question 10

Three statements are followed by three conclusions numbered I, II and III. You have to consider these statements to be true, even if they seem to be at variance with commonly known facts. Decide which of the given conclusions logically follow/s from the given statement.

Statement:

Some circle are rectangle.

Some square are triangle.

No square are rectangle.

Conclusions:

(I) All squares are rectangle.

(II) Some squares are rectangle.

(III) No rectangle are square.

  1. AOption (a)

    Only I follow

  2. BOption (b)

    Only II follows

  3. COption (c)

    Only III follows

  4. DOption (d)

    Either I or II follows

View answer & explanation

Correct answer

Answer: (c)C.

Only III follows

Why this answer is correct

Statement:

Some circle are rectangle.

Some square are triangle.

No square are rectangle.

The least possible diagram for the given statements is as follows:

Conclusions:

(I) All squares are rectange → False (Because 'No square are rectangle', so it is definitely false)

(II) Some squares are rectangle.→ False (Because 'No square are rectangle', so it is definitely false)

(III) No rectangle are square.→ True (Because 'No square are rectangle', so it is definitely true)

Hence, the correct answer is "Only III follows".

Question 11

Select the set of numbers that is similar to the following set of numbers.

Given set: (3, 18, 36)

  1. AOption (a)

    (2, 10, 16)

  2. BOption (b)

    (4, 24, 48)

  3. COption (c)

    (6, 42, 48)

  4. DOption (d)

    (12, 72, 96)

View answer & explanation

Correct answer

Answer: (b)B.

(4, 24, 48)

Why this answer is correct

The logic follows here is,

(First number) × 6 = (Second term)

(Second term) × 2 = (Third number)

Given set: (3, 18, 36)

→ 3 × 6 = 18

→ 18 × 2 = 36

Similarly, 

  • (4, 24, 48)

→ 4 × 6 = 24

→ 24 × 2 = 48

Hence, the correct answer is "(4, 24, 48)".

Question 12

In the question below, a statement is followed by two conclusions. Study the conclusions and select the correct option as the answer.

Statements:

A ≥ B > C, D > M ≤ K, D ≥ C

Conclusion:

I. C < M

II. B > K

  1. AOption (a)

    If only conclusion I is true

  2. BOption (b)

    If only conclusion II is true

  3. COption (c)

    If either conclusion I or II is true

  4. DOption (d)

    If neither conclusion I nor II is true

View answer & explanation

Correct answer

Answer: (d)D.

If neither conclusion I nor II is true

Why this answer is correct

Given statement : A ≥ B > C, D > M ≤ K, D ≥ C

On combining:  A ≥ B > C < D > M ≤ K

Conclusions :

I. C < M → FALSE (as  A ≥ B > C < D > M ≤ K → clear relationship between C and M cannot be determined).

II. B > K →  FALSE (as  A ≥ B > C < D > M ≤ K →  clear relationship between B and K cannot be determined).

Hence, the correct answer is "If neither conclusion I nor II is true".

Question 13

In the following question, select the missing number from the given series.

76, 80, 107, 123, ?, 284

  1. AOption (a)

    248

  2. BOption (b)

    250

  3. COption (c)

    252

  4. DOption (d)

    254

View answer & explanation

Correct answer

Answer: (a)A.

248

Why this answer is correct

Given: 76, 80, 107, 123, ?, 284

The logic follows here is:

Hence, the correct answer is "248".

Question 14

In the following figure, triangle represents photographer, circle represents fashion photography, hexagon represents sports photography, rectangle represents editorial photography and square represents wildlife photography.

What does letter 'C' represent? 

  1. AOption (a)

    Photographer who do fashion photography and sports photography only

  2. BOption (b)

    Photographer who do fashion photography and wildlife photography only

  3. COption (c)

    Photographer who do fashion photography, editorial photography and wildlife photography only

  4. DOption (d)

    Photographer who do fashion photography and editorial photography only

View answer & explanation

Correct answer

Answer: (b)B.

Photographer who do fashion photography and wildlife photography only

Why this answer is correct

As per the given information,

The shaded part i.e. C represents → Photographer who do fashion photography and wildlife photography only

Hence, the correct answer is "option (2)".

Question 15

In the following figure, triangle represents video games, circle represents music, hexagon represents cell phones, rectangle represents books and square represents teenagers.

What does letter 'A' represent?

  1. AOption (a)

    Teenagers who spend their free time in video games, cell phones and books only

  2. BOption (b)

    Teenagers who spend their free time in video games, music and books only

  3. COption (c)

    Teenagers who spend their free time in video games and books only

  4. DOption (d)

    Teenagers who spend their free time in video games and cell phones only

View answer & explanation

Correct answer

Answer: (b)B.

Teenagers who spend their free time in video games, music and books only

Why this answer is correct

As per the given information,

The shaded part i.e. A represents →Teenagers who spend their free time in video games, music and books only

Hence, the correct answer is "option (2)".

Question 16

Select the figure that will replace the question mark (?) in the following figure series.

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (b)B.

Why this answer is correct

The logic follows here is:

The figure has a circle, a hexagon and a rhombus. The circle and rhombus is divided into 4 parts while hexagon is divided into 8 parts. Each part of them is filled in clockwise direction in each successive figure.

So, the figure that will replace the question mark (?) in the following figure series is shown below :

Thus, the figure in option (2) will be the next image for the given series.

Hence, the correct answer is "option (2)".

Question 17

From the given alternatives select the one in which the question figure is hidden/embedded.

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (c)C.

Why this answer is correct

On close observation, we find that the problem figure is embedded in option (3) as shown below :

Hence, the correct answer is "option (3)".

Question 18

From the given alternatives select the one which is the mirror image of given Question Figure.

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (b)B.

Why this answer is correct

The logic follows here is:

When the mirror is placed on the line MN, the left side and right side changed vice-versa where the top and bottom remain the same.

Thus, the correct mirror image of the given figure will be :

Hence, the correct answer is "Option 3".

Additional Information

In Mirror image left side and right side changed vice-versa where top and bottom remain the same.

Reflection of an object into the water is its water image. It appears by inverting an object vertically i.e. upside down.

The water image of the figure looks like mirror image of the figure in case the mirror is horizontally at the bottom of the figure.

Water image is just a reflection where top and bottom part of the images changed where left and right side of the image remain same.

Mistake PointsBoth option 2 and 4 are different, Please check the difference below:

Option 2) 

 Option 4)

Question 19

Find the number of square in the given figure.

  1. AOption (a)

    10

  2. BOption (b)

    11

  3. COption (c)

    12

  4. DOption (d)

    13

View answer & explanation

Correct answer

Answer: (b)B.

11

Why this answer is correct

As per the given question:

The numbers of squares in the given figures are:

Thus, there are '11' squares in the given figures.

Hence, the correct answer is "11".

Question 20

From the given alternatives select the one that will complete the question figure.

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (b)B.

Why this answer is correct

As per the information:

When the question figure is merged with the figure in option (2), the complete figure can be seen as:

Hence, the correct answer is "option (2)".

General Awareness (20 questions)

Question 21

Sheesh Mahal or the 'Palace of Mirrors' in Patiala (Punjab) was built by _______.

  1. AOption (a)

    Maharaja Harpreet Singh

  2. BOption (b)

    Maharaja Virendra Singh

  3. COption (c)

    Maharaja Harbhajan Singh

  4. DOption (d)

    Maharaja Narinder Singh

View answer & explanation

Correct answer

Answer: (d)D.

Maharaja Narinder Singh

Why this answer is correct

The correct answer is Maharaja Narinder Singh.

Key Points

  • Maharaja Narinder Singh (1845-1862): Sheesh Mahal was built by Maharaja Narinder Singh during his reign.
  • It served as a comfortable residence for the Maharaja.
  • Architectural Significance: Sheesh Mahal is renowned for its exquisite architecture and interior decoration, especially using mirrors on the walls and ceilings.
  • Museum: Currently, Sheesh Mahal functions as a museum showcasing a variety of artifacts and historical items.
  • Cultural Importance: The palace holds cultural and historical significance, reflecting the region's rich heritage.
  • Tourist Attraction: Sheesh Mahal is a major tourist attraction in Patiala, drawing visitors with its splendid design and historical value.

Additional Information

  • Maharaja Harpreet Singh - His name does not appear prominently in the history of Patiala or the construction of notable monuments.
  • Maharaja Virendra Singh - His contributions lie elsewhere in the history of Punjab, possibly in administrative or military affairs.

Question 22

Which state is associated with Warli folk paintings?

  1. AOption (a)

    Maharashtra

  2. BOption (b)

    Madhya Pradesh

  3. COption (c)

    Himachal Pradesh

  4. DOption (d)

    Chhattisgarh

View answer & explanation

Correct answer

Answer: (a)A.

Maharashtra

Why this answer is correct

The correct answer is Maharashtra.

Key Points

  • Origin: Warli folk paintings originated from the Warli tribe, one of the largest tribes found in Maharashtra.
  • These paintings are primarily from the North Sahyadri Range in Maharashtra, including areas of Dahanu, Talasari, Jawhar, Palghar, Mokhada, and Vikramgad.
  • The paintings are characterized by their simple, monochromatic style, using white pigment on a mud base.
  • Common themes include everyday life, nature, and social events, depicted in a highly stylized manner.
  • Warli paintings hold cultural and spiritual importance for the Warli people, often used to mark auspicious occasions and festivals.

Additional Information

StateImportant Information
MaharashtraMaharashtra is the state where Warli folk paintings originated. The Warli tribe is indigenous to this region.
Madhya PradeshMadhya Pradesh is known for other traditional arts like Gond paintings.
Himachal PradeshHimachal Pradesh has its own unique art forms such as Kangra paintings and Pahari miniatures.
ChhattisgarhChhattisgarh is known for its tribal art forms. It has traditions like Bastar art and Pithora paintings.

Question 23

Radio Broadcasting started in India in the early ________.

  1. AOption (a)

    1920's

  2. BOption (b)

    Mid 1940's & 1950's

  3. COption (c)

    1940's

  4. DOption (d)

    Mid 1930's & 1940's

View answer & explanation

Correct answer

Answer: (a)A.

1920's

Why this answer is correct

The correct answer is 1920's

Key Points

  • Radio broadcasting in India began in 1923 with the establishment of the Radio Club of Bombay.
  • The first radio broadcast in India took place on June 23, 1923, by the Radio Club of Bombay.
  • In 1927, the Indian Broadcasting Company (IBC) was formed and started broadcasting from Bombay and Calcutta.
  • In 1930, the Indian Broadcasting Service (IBS) under the Department of Industries and Labour was started, and later it was renamed All India Radio (AIR) in 1936.
  • This marked the beginning of organized radio broadcasting in India, leading to the establishment of various radio stations across the country..

Question 24

The title of the Maharajadhiraja is associated with which of the following ruler?

  1. AOption (a)

    Yasodharman

  2. BOption (b)

    Chandragupta I

  3. COption (c)

    Ghatotkacha

  4. DOption (d)

    Samudragupta

View answer & explanation

Correct answer

Answer: (b)B.

Chandragupta I

Why this answer is correct

The correct answer is Chandragupta I.

Key Points

  • Chandragupta I was the first ruler of the Gupta dynasty to adopt the title of Maharajadhiraja.
  • Chandragupta I was a son of the Gupta king Ghatotkacha, and a grandson of the dynasty's founder Gupta, both of whom are called Maharaja in the Allahabad Pillar inscription.
  • He was also the father of Samudragupta, his next successor.
  • Chandragupta I married the Lichchhavi princess Kumaradevi.
  • Lichchhavi is the name of an ancient clan that was headquartered at Vaishali in present-day Bihar during the time of Gautama Buddha.

Additional Information

Gupta Dynasty:

  • The founder of the Gupta dynasty was Sri Gupta.
  • He was succeeded by Ghatotkacha. These two were called Maharajas.
  • The next ruler was Chandragupta I and he was the first to be called Maharajadhiraja.
  • Chandragupta, I was succeeded by Samudragupta in about 330 A.D., who reigned for about fifty years.
  • He was a great military genius and is said to have commanded a military campaign across the Deccan, and also subdued the forest tribes of the Vindhya region.
  • Samudragupta's successor Chandragupta II, also known as Vikramaditya, conquered the extensive territories of Malwa, Gujarat and Kathiawar.

Important Points

  • Some famous events during the rule of Gupta Kings:
  • The famous Chinese pilgrim, Fahien visited India during the reign of Chandragupta II.
  • Out of his nine years of stay in India, he spent six years in the Gupta empire.
  • Chandragupta II waged war against the Saka satraps of western India.
  • Rudrasimha III, the last ruler of the Saka satrap was defeated, dethroned, and killed. His territories in western Malwa and the Kathiawar Peninsula were annexed into the Gupta Empire.
  • Kumaragupta laid the foundation of Nalanda University.

Question 25

On January 26, 1950, the Constitution came into force and Dr. Rajendra Prasad was elected the ______.

  1. AOption (a)

    First Vice President of India

  2. BOption (b)

    First Home minister of India

  3. COption (c)

    First President of India

  4. DOption (d)

    First foreign minister of India

View answer & explanation

Correct answer

Answer: (c)C.

First President of India

Why this answer is correct

The correct answer is First President of India.

Key Points

  • The Constitution of India was drafted by the Constituent Assembly.
  • It was implemented under the Cabinet Mission Plan on 16 May 1946.
  • The members of the Constituent Assembly were elected by the provincial assemblies by a single, transferable-vote system of proportional representation.
  • Dr Rajendra Prasad was the president of the constituent assembly.

Additional Information

  • The members of the Constituent Assembly were elected by Provincial legislative councils.
  • They elected people from the whole country to represent every area.
  • It was elected in December and the first meeting in 1946.
  • It came to force on 26th January 1950.
  • Dr BR Ambedkar was the chairman of the Drafting Committee.

Question 26

Which of the following was the fifth Guru of Sikhism?

  1. AOption (a)

    Guru Amar Das

  2. BOption (b)

    Guru Angad Dev

  3. COption (c)

    Guru Arjan Dev

  4. DOption (d)

    Guru Siri Har Krishan

View answer & explanation

Correct answer

Answer: (c)C.

Guru Arjan Dev

Why this answer is correct

The correct answer is Guru Arjan Dev.

Key Points

  • Guru Arjan Dev was the fifth guru from 1581 to 1606.
  • He became the first great martyr in Sikh history when Emperor Jahangir ordered his execution. Thus, he was hailed as Shaheedan-de-Sartaj (The crown of martyrs).
  • He compiled the Adi Granth, the scriptures of the Sikhs.
  • He completed construction of Sri Darbar Sahib also known as Golden Temple in Amritsar.
  • He founded the town of Tarn Taran Sahib near Goindwal Sahib.

Additional Information

  • Ten Sikh Gurus with Timeline
Guru Nanak Dev1469-1539
Guru Angad Dev1539-1552
Guru Amardas Sahib1552-1574
Guru Ram Das1574-1581
Guru Arjan Dev1581-1606
Guru Har Gobind Sahib1606-1644
Guru Har Rai Sahib1644-1661
Guru Har Krishan Sahib1661-1664
Guru Tegh Bahadur Sahib1665-1675
Guru Gobind Singh Sahib1675-1708

Question 27

The 2021 India-Indonesia CORPAT which took place in July 2021 was which edition of the biannual event?

  1. AOption (a)

    32nd

  2. BOption (b)

    36th

  3. COption (c)

    31st

  4. DOption (d)

    30th

View answer & explanation

Correct answer

Answer: (b)B.

36th

Why this answer is correct

The correct answer is 36th.

In News

  • Dates and Location: The 42nd India-Indonesia Coordinated Patrol (IND-INDO CORPAT) took place from May 22 to 24, 2024, in Sabang, Indonesia.
  • Participating Indian Ships: INS Kulish, NAVCC, and INS Chetlat.
  • Objectives: Enhancing maritime cooperation, addressing common maritime challenges like piracy, smuggling, and illegal fishing, and fostering the long-standing partnership between India and Indonesia.
  • Activities: Included joint patrol operations, high-level strategic meetings, cultural exchanges, and debriefing sessions to review joint operations and plan future collaborations.
ElementDetails
DatesMay 22 to 24, 2024
LocationSabang, Indonesia
Participating Indian ShipsINS Kulish, NAVCC, INS Chetlat
ObjectivesEnhance maritime cooperation, address common maritime challenges, strengthen India-Indonesia partnership
ActivitiesJoint patrol operations, high-level meetings, cultural exchanges, debriefing sessions
SignificanceReinforced maritime security and stability in the Indian Ocean region through bilateral cooperation

Key Points

  • The 36th edition of India-Indonesia coordinated patrol (CORPAT) between the Indian Navy and the Indonesian Navy concluded on July 31, 2021.
  • INS Saryu undertook coordinated patrol (CORPAT) with Indonesian Naval Ship KRI Bung Tomo from July 30 to 31.
  • The CORPAT between India and Indonesia also witnessed the participation of Maritime Patrol Aircraft from both nations.

Question 28

Who is the current CEO of Bharat BillPay?

  1. AOption (a)

    A.K. Singh

  2. BOption (b)

    Sudhansu Dhulia

  3. COption (c)

    P Ravikrishna

  4. DOption (d)

    Noopur Chaturvedi

View answer & explanation

Correct answer

Answer: (d)D.

Noopur Chaturvedi

Why this answer is correct

The correct answer is Noopur Chaturvedi.

Key Points

  • Bharat Bill Payment System has appointed former PayU and Airtel Payments Bank executive Noopur Chaturvedi as its new CEO.
  • Chaturvedi, prior to this appointment, was the country head for small and medium business at PayU.
  • She has earlier worked with Airtel Payments Bank, Samsung, ING Vysya Bank, and Citibank in various senior roles.

Additional Information

NamePosition
A.K. SinghChairman and Managing Director, NHPC
Sudhansu DhuliaJudge, Supreme Court of India
P. RavikrishnaCEO, ONGC Petro additions Limited (OPaL)

Question 29

Which of the following laws created a favourable environment for women to secure freedom and self-development?

  1. AOption (a)

    Right to Information

  2. BOption (b)

    Dowry Prohibition Act

  3. COption (c)

    Food Security Act

  4. DOption (d)

    Policy of Reservation

View answer & explanation

Correct answer

Answer: (b)B.

Dowry Prohibition Act

Why this answer is correct

The correct answer is Dowry Prohibition Act.

Key Points

  • Dowry Prohibition Act was enacted on May 1, 1961:
  • Its purpose was to prevent the giving and receiving of dowry.
  • According to the Dowry Prohibition Act, "dowry" means any property or valuable security given or agreed to be given directly or indirectly.
  • The Dowry Prohibition Act is applicable to persons of all religions in India.
  • Punishment for violation of law is 5 years imprisonment and Rs 15000/- or the value of dowry whichever is higher.
  • Amendment: The 1984 Act required the maintenance of a list describing the identity of the person giving each gift, its value, as a gift given to the bride and groom at the time of marriage.
  • Amendments were also made to the original Dowry Prohibition Act to establish maximum and minimum penalties for giving and receiving dowry.
  • Proposals to demand dowry or to advertise money or property in connection with marriage shall be fined.

Additional Information

  • Right to Information - Empowers citizens to request information from public authorities.
  • Promotes transparency and accountability in governance.
  • Food Security Act - Aims to provide subsidized food grains to two-thirds of India's population.
  • Known as the National Food Security Act, 2013.
  • Policy of Reservation - Provides reservations in education and employment for Scheduled Castes, Scheduled Tribes, and Other Backward Classes.
  • Promotes social equality by supporting historically disadvantaged groups.

Question 30

The unit of Electromotive force of a cell is _______.

  1. AOption (a)

    Joule

  2. BOption (b)

    Ampere

  3. COption (c)

    Dyne

  4. DOption (d)

    Volt

View answer & explanation

Correct answer

Answer: (d)D.

Volt

Why this answer is correct

The unit of Electromotive force of a cell is Volt.

Key Points

  • Electromotive force is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field.
  • It is given by the formula  E= V + Ir
  • Where,
  • V is the voltage of the cell
  • I is the current across the circuit
  • r is the internal resistance of the cell
  • E is the electromotive force
  • Volt is the unit for electromotive force.
  • EMF dimension is given as M1L2T-3I-1.

 

Additional Information

  • Potential Difference:
  • Work done in bringing a unit positive charge from one point to another point is the potential difference between the two points.
  • Its SI unit is volt and it is a scalar quantity.
  • Resistance:
  • The opposition offered by a conductor to the flow of current through it is called resistance.
  • Its SI unit is ohm.

Question 31

What are the pores in a leaf called through which respiratory exchange of gases takes place?

  1. AOption (a)

    Vacuoles

  2. BOption (b)

    Lenticels

  3. COption (c)

    Stomata

  4. DOption (d)

    Xylem

View answer & explanation

Correct answer

Answer: (c)C.

Stomata

Why this answer is correct

The correct answer is Stomata.

Explanation:

  • Plants, unlike animals, don't have lungs for breathing.
  • But they still need to take in oxygen (O₂) for cellular respiration and release carbon dioxide (CO₂) as a byproduct.
  • This vital gas exchange happens through specialized pores on the leaf surface called stomata (singular: stoma).

Structure:

  • Stomata are microscopic openings surrounded by two specialized cells called guard cells. These guard cells are bean-shaped and have unique properties that allow them to open and close the stomatal pore. The guard cells contain chloroplasts, which play a role in regulating their opening and closing.

Function:

  • Gas Exchange: Stomata act as gateways for gases like carbon dioxide (CO₂) to enter the leaf for photosynthesis and oxygen (O₂) to leave as a waste product of respiration. They also allow water vapor to escape during transpiration, a process that helps regulate plant temperature and water balance.
  • Regulation: The opening and closing of stomata are crucial for maintaining a balance between these gas exchanges and water conservation. Guard cells control the size of the stomatal pore based on various factors like light intensity, CO₂ concentration, and humidity.
  • Light: In the presence of sunlight, guard cells take up potassium ions and become turgid (swollen with water), causing the stomatal pore to open for photosynthesis.
  • CO₂ Concentration: When CO₂ levels decrease inside the leaf due to photosynthesis, stomata tend to open wider to allow more CO₂ intake.
  • Humidity: During dry periods, stomata close to minimize water loss through transpiration.

Importance:

  • Enable Photosynthesis: By allowing CO₂ intake, stomata facilitate the process of photosynthesis, where plants capture sunlight energy to produce food (glucose).
  • Regulate Water Balance: The opening and closing of stomata help plants control water loss through transpiration. This is especially important in dry environments where water conservation is vital.
  • Maintain Optimal Gas Exchange: Stomata regulate the intake of oxygen for cellular respiration and the release of respiratory CO₂.

Additional InformationStomata are typically found on the underside of leaves to minimize water loss through wind exposure.

The number and distribution of stomata can vary depending on the plant species and its environment. Plants adapted to dry environments may have fewer stomata or stomata located in sunken pits to reduce water loss.

Some plants have special adaptations to control gas exchange, such as crassulacean acid metabolism (CAM) photosynthesis, where CO₂ uptake occurs at night when stomata are closed to minimize water loss.

Question 32

In the manufacture of steel, Iron ore, coking coal and lime stone are required in the ratio of approximately _____.

  1. AOption (a)

    2 ∶ 4 ∶ 1

  2. BOption (b)

    1 ∶ 4 ∶ 2

  3. COption (c)

    4 ∶ 3 ∶ 1

  4. DOption (d)

    4 ∶ 2 ∶ 1

View answer & explanation

Correct answer

Answer: (d)D.

4 ∶ 2 ∶ 1

Why this answer is correct

Explanation:

Blast Furnace and Steel Production Ratio

  • Steel is an alloy where iron is the main component, typically containing around 2% carbon and other elements to enhance its properties.
  • Iron ore, rich in iron oxide (Fe O), undergoes refinement to remove oxygen before becoming steel. This process takes place in a large furnace called a blast furnace.
  • Inside the blast furnace, iron ore, coking coal, and limestone react at high temperatures (around 1500°C).
  • Iron Ore:  The primary source of iron. The iron oxide (FeO) within the ore needs separation from oxygen.
  • Coking coal: This special type of coal burns with minimal smoke or ash. During the process, carbon in the coal reacts with oxygen in the iron oxide, removing oxygen from the iron (reduction). This leaves behind pure iron. Additionally, the burning coal generates heat to maintain the high temperatures needed in the blast furnace.
  • Limestone:   Acting as a flux, limestone lowers the melting point of the materials inside the furnace. This allows unwanted materials like slag (impurities from the ore and limestone) to become more fluid and separate from the molten iron.

Ratio of Iron Ore, Coking Coal, and Limestone

  • The ratio of iron ore, coking coal, and limestone used in a blast furnace isn't a fixed number, but it's typically around 4:2:1 (iron ore : coking coal : limestone).
  • Iron Ore: This is the main product we want to extract, so it needs the largest proportion.
  • Coking Coal: Enough coal is needed to provide sufficient heat for the process and remove oxygen from the iron ore. However, using too much coal can increase the carbon content in the final steel product.
  • Limestone: Enough limestone is needed to create a good slag for efficient removal of impurities. Using too much limestone can be wasteful, while too little can lead to problems with slag removal.

 Key Points

The exact ratio can vary depending on several factors, including:

  • The quality of the iron ore (higher quality ore may require less)
  • The desired properties of the final steel product (higher carbon content might require slightly more coal)
  • The efficiency of the blast furnace design

By carefully controlling the ratio of these materials, steel manufacturers can optimize the production process and create high-quality steel.

Question 33

________ refers to the existence of more than one level of government in the country. 

  1. AOption (a)

    Socialism

  2. BOption (b)

    Federalism

  3. COption (c)

    Secularism

  4. DOption (d)

    Democracy

View answer & explanation

Correct answer

Answer: (b)B.

Federalism

Why this answer is correct

The correct answer is Federalism.

Key Points

  • India is a federal system but with more tilt towards a unitary system of government.
  • It is sometimes considered a quasi-federal system as it has features of both a federal and a unitary system.
  • Article 1 of the Indian Constitution states, ‘India, that is Bharat, shall be a union of states.
  • The word federation is not mentioned in the constitution.
  • India is a holding together type of Federation in which some States have more power than others.
  • Indian federalism resembles the Canadian model.
  • Article 1 describes India as a Union of states.
  • It is not a result of an agreement between states and states have no right to secede from the federation.
  • It’s an Indestructible union of destructible states.
  • Different scholars have different opinions on the federal structure of India.
  • K.C. Wheare described it as “Quasi federalism”.
  • Granville Austin called it “Cooperative federalism” (need for national integrity and unity).
  • Morris Jones defined it as 'Bargaining Federalism'.
  • Ivor Jenning described it as "Federalism with Centralizing tendency".

Question 34

The image formed on the retina of the human eye is ______.

  1. AOption (a)

    Virtual and Erect

  2. BOption (b)

    Real and Erect

  3. COption (c)

    Virtual and Inverted

  4. DOption (d)

    Real and Inverted

View answer & explanation

Correct answer

Answer: (d)D.

Real and Inverted

Why this answer is correct

The correct answer is Real and inverted.

Key Points 

  • The image formed on the retina of the human eye is real and inverted.
  • The retina comprises specialized cells that are sensitive to light, known as rod and cone cells.
  • These cells get stimulated and send signals to the brain which turns them into erect images that allow us to see.

Additional Information 

  • The lens system of an eye forms an image on a light-sensitive screen known as the retina.
  • Light enters the eye through a thin membrane known as the cornea.
  • Behind the cornea, there is a structure, known as the iris. It has a major function to control the size of the pupil.

Question 35

What is surplus budget?

  1. AOption (a)

    Income and expenditure are equal

  2. BOption (b)

    Revenue more than the expenditure

  3. COption (c)

    Expenditure more than revenue

  4. DOption (d)

    Revenue less than expenditure

View answer & explanation

Correct answer

Answer: (b)B.

Revenue more than the expenditure

Why this answer is correct

The correct answer is Revenue more than the expenditure

Key Points 

  • A budget surplus occurs when receipts exceed expenditures.
  • The term often refers to a government's financial state, as individuals have "savings" rather than a "budget surplus".
  • A surplus is an indication that a government's finances are being effectively managed.
  • A surplus implies the government has extra funds.
  • Advantages of a budget surplus:
  • These funds can be allocated toward public debt, which reduces interest rates and helps the economy.
  • A budget surplus can be used to reduce taxes, start new programs, or fund existing programs such as Social Security or Medicare.
  • The government might use a budget surplus to cut taxes to stimulate the supply-side of the economy.

Question 36

What is the full form of ADCCI?

  1. AOption (a)

    Asian Chamber of Commerce and Industry

  2. BOption (b)

    American Chamber of Commerce and Industry

  3. COption (c)

    Abu Dhabi Chamber of Commerce and Industry

  4. DOption (d)

    Abu Dhabi Chamber of commercial and industrial

View answer & explanation

Correct answer

Answer: (c)C.

Abu Dhabi Chamber of Commerce and Industry

Why this answer is correct

The correct answer is Abu Dhabi Chamber of Commerce and Industry.

Key Points

  • Abu Dhabi Chamber of Commerce and Industry (ADCCI): ADCCI is a prominent organization based in Abu Dhabi, United Arab Emirates.
  • It aims to promote economic growth and development in Abu Dhabi by supporting local businesses and facilitating trade and investment.
  • Significance: The Chamber plays a crucial role in representing the interests of the business community and provides various services, including business support, networking opportunities, and policy advocacy.

Question 37

In which of the following state of India, you will find the natural phenomenon called Chir Batti?

  1. AOption (a)

    Gujarat

  2. BOption (b)

    Karnataka

  3. COption (c)

    Kerala

  4. DOption (d)

    Tamil Nadu

View answer & explanation

Correct answer

Answer: (a)A.

Gujarat

Why this answer is correct

The correct answer is Gujarat.

Key Points

  • Chir Batti is a natural phenomenon observed in the Banni grasslands and the Rann of Kutch in Gujarat.
  • Chir Batti translates to "ghost lights" and refers to mysterious glowing orbs that appear in the region, often described as floating lights.
  • These lights are typically visible on dark nights and are known to change color, size, and shape, moving at varying speeds.
  • The phenomenon has attracted interest from scientists and researchers, though its exact cause remains a mystery.
  • Locally, Chir Batti holds cultural and folkloric importance, often featuring in stories and legends of the Kutch region.
  • The enigmatic nature of Chir Batti has made it a point of curiosity and attraction for tourists visiting the Rann of Kutch.

Question 38

Who has been awarded the 2019 Golden Foot award?

  1. AOption (a)

    Lionel Messi

  2. BOption (b)

    Wayne Rooney

  3. COption (c)

    Neymar

  4. DOption (d)

    Luka Modric

View answer & explanation

Correct answer

Answer: (d)D.

Luka Modric

Why this answer is correct

The correct answer is Luka Modric.

Key Points 

  • Luka Modric is a professional football player from Croatia.
  • He won the golden foot award in 2019.
  • He was awarded the ‘FIFA player of the year 2018’
  • He received the golden ball award for the best player in the 2018 FIFA World Cup.
  • He won the Ballon d'Or award in 2018.
  • He won the UEFA Men's player of the year award 2017-2018 and became the first Croatian player to win this award.
  • He represented Croatia in 2006, 2014, and 2018 FIFA World Cups.

Additional Information 

  • Christiano Ronaldo was awarded the ‘FIFA Player of the year 2017'.
  • Lionel Messi was awarded the ‘FIFA Player of the year 2019'.
  • Mohamed Salah is a professional footballer from Egypt.

Question 39

Padma Sachdev is associated with which of the following profession?

  1. AOption (a)

    Poet, writer

  2. BOption (b)

    Politician

  3. COption (c)

    Journalist

  4. DOption (d)

    Singer

View answer & explanation

Correct answer

Answer: (a)A.

Poet, writer

Why this answer is correct

The correct answer is Poet, writer.

Key Points

  • Profession: Padma Sachdev is renowned as a poet and writer.
  • Languages: She primarily wrote in Dogri and Hindi, contributing significantly to Dogri literature
  • Achievements: Padma Sachdev has received several awards for her literary works, including the Sahitya Akademi Award and the Padma Shri.
  • Notable Works: Her famous works include "Meri Kavita Mere Geet" and "Amar Kahani".
  • Cultural Impact: She is celebrated for her poetic expression and contribution to Indian literature, especially in bringing Dogri language to the forefront.
  • Recognition: Her writings have been instrumental in preserving and promoting regional literature and culture.

Question 40

Chandrakanta, written by _____, is considered to be the first work of prose in Hindi.

  1. AOption (a)

    Mahadevi Varma

  2. BOption (b)

    Devaki Nandan Khatri

  3. COption (c)

    Sumitranandan Pant

  4. DOption (d)

    Maithili Sharan Gupt

View answer & explanation

Correct answer

Answer: (b)B.

Devaki Nandan Khatri

Why this answer is correct

The correct answer is Devaki Nandan Khatri.

Key Points

  • Devaki Nandan Khatri: Chandrakanta was written by Devaki Nandan Khatri and is considered one of the first works of prose in Hindi literature.
  • Historical Significance: Published in 1888, it played a significant role in popularizing Hindi as a literary language.
  • Popularity: The novel gained immense popularity and has been adapted into various television series and films.
  • Literary Influence: Chandrakanta's success inspired many other writers to adopt Hindi for their prose works.

Additional Information

AuthorNotable Works
Mahadevi Varma- Yama - Neeharika - Deepshikha
Devaki Nandan Khatri- Chandrakanta - Chandrakanta Santati - Bhootnath
Sumitranandan Pant- Pallav - Gunjan - Swarna Kiran
Maithili Sharan Gupt- Saket - Bharat-Bharati - Jayadrath Vadh

Arithmetic Ability (20 questions)

Question 41

If x13+y13=6x^{\frac{1}{3}}+y^{\frac{1}{3}}=6 and x13−y13=2,xy=?x^{\frac{1}{3}}-y^{\frac{1}{3}}=2, x y=?

  1. AOption (a)

    1331

  2. BOption (b)

    81

  3. COption (c)

    512

  4. DOption (d)

    64

View answer & explanation

Correct answer

Answer: (c)C.

512

Why this answer is correct

Given:

 x13+y13=6x^{\frac{1}{3}}+y^{\frac{1}{3}}=6 and x13−y13=2x^{\frac{1}{3}}-y^{\frac{1}{3}}=2

Formula used:

  1. (a + b)2 = a2 + b2 + 2ab
  2. (a - b)2 = a2 + b2 - 2ab

Calculation:

According to the question,

⇒ x13+y13=6x^{\frac{1}{3}}+y^{\frac{1}{3}}=6 

Take square on both sides,

⇒ (x13+y13)2=62(x^{\frac{1}{3}}+y^{\frac{1}{3}})^2=6^2 

⇒ (x23+y23+2x13y13)(x^{\frac{2}{3}}+y^{\frac{2}{3}} + 2x^{\frac{1}{3}}y^{\frac{1}{3}})  = 36    ---(i)

Now,

⇒  x13−y13=2x^{\frac{1}{3}}-y^{\frac{1}{3}}=2

⇒  (x13−y13)2=22(x^{\frac{1}{3}}-y^{\frac{1}{3}})^2=2^2

⇒  (x23+y23−2x13y13)(x^{\frac{2}{3}}+y^{\frac{2}{3}} - 2x^{\frac{1}{3}}y^{\frac{1}{3}}) = 4     ---(ii)

On subtracting equation (ii) from (i),

⇒ 4x13y13=324x^{\frac{1}{3}}y^{\frac{1}{3}}=32

⇒ x13y13x^{\frac{1}{3}}y^{\frac{1}{3}} = 8

Take cube on both sides, 

⇒ xy = 512

Therefore, '512' is the required answer.

Question 42

What value will come in place of question mark (?) in the following question?

713+413+212+512=?−4137\frac{1}{3}+4\frac{1}{3}+2\frac{1}{2}+5\frac{1}{2}=?-4\frac{1}{3}

  1. AOption (a)

    24

  2. BOption (b)

    22

  3. COption (c)

    21

  4. DOption (d)

    25

View answer & explanation

Correct answer

Answer: (a)A.

24

Why this answer is correct

Given:

The given expression:

713+413+212+512=?−4137\frac{1}{3}+4\frac{1}{3}+2\frac{1}{2}+5\frac{1}{2}=?-4\frac{1}{3}

Calculation:

According to the question:

⇒ 713+413+212+512=?−4137\frac{1}{3}+4\frac{1}{3}+2\frac{1}{2}+5\frac{1}{2}=?-4\frac{1}{3}

⇒ (223)+(133)+(52)+(112)=?−(133) (\frac{22}{3} )+ (\frac{13}{3} )+ (\frac{5}{2} )+ (\frac{11}{2} )=?- (\frac{13}{3} )

⇒ (446)+(266)+(156)+(336)=?−(266) (\frac{44}{6} )+ (\frac{26}{6} )+ (\frac{15}{6} )+ (\frac{33}{6} )=?- (\frac{26}{6} )

⇒ (446)+(266)+(156)+(336)+(266)=? (\frac{44}{6} )+ (\frac{26}{6} )+ (\frac{15}{6} )+ (\frac{33}{6} )+ (\frac{26}{6} )=?

⇒ ? = (1446) (\frac{144}{6} ) = 24

Therefore, "24" is the required answer.

Question 43

What value will come in place of question mark (?) in the following question?

(9)3 + (2)3 + 3(9 × 2) 11 = ?

  1. AOption (a)

    625

  2. BOption (b)

    700

  3. COption (c)

    765

  4. DOption (d)

    1331

View answer & explanation

Correct answer

Answer: (d)D.

1331

Why this answer is correct

Given:

The given expression:

(9)3 + (2)3 + 3(9 × 2) 11 = ?

Calculation:

According to the question,

⇒ (9)3 + (2)3 + 3(9 × 2) 11 = ?

⇒ 729 + 8 + 594 = ?

⇒ ? = 1331

Therefore, "1331" is the required answer.

Question 44

Find the greatest number which divides 882,396 and 1404 exactly.

  1. AOption (a)

    22

  2. BOption (b)

    18

  3. COption (c)

    16

  4. DOption (d)

    14

View answer & explanation

Correct answer

Answer: (b)B.

18

Why this answer is correct

Given:

The given numbers are: 882, 396 and 1404.

Concept:

The highest number that divides a, b and c exactly is H.C.F of a, b and c.

Calculation:

Prime factorisation of the given numbers:

882 = 2 × 3 × 3 × 7 × 7

396 = 2 × 2 × 3 × 3 × 11

1404 = 2 × 2 × 3 × 3 × 3 × 13

Now, the common factors in all three numbers are = 2, 3, 3

Therefore, H.C.F = 2 × 3 × 3 = 18

The greatest number which divides 882,396 and 1404 exactly = 18

Therefore, '18' is the required answer.

Question 45

In the set of first 100 multiples of 5, P is the average of the multiples on the odd places and Q is the average of the multiples on the even places. By what number, the value of Q is more than P?

  1. AOption (a)

    5

  2. BOption (b)

    10

  3. COption (c)

    2.5

  4. DOption (d)

    12.5

View answer & explanation

Correct answer

Answer: (a)A.

5

Why this answer is correct

Shortcut Trick

Each even-placed multiple is exactly 5 more than its preceding odd-placed multiple.

Multiples: (5, 10), (15, 20), (25, 30), ... (495, 500).

Difference between every pair (Even − Odd) = 5.

Therefore, Average of Even (Q) − Average of Odd (P) = Constant difference = 5.

∴ The correct answer is 5.

Alternate Method

Given: First 100 multiples of 5: {5, 10, 15, 20, ..., 500}

Formula Used: Average of an Arithmetic Progression (AP) = (First term + Last term) ÷ 2

⇒ Set P (Odd places): 1st, 3rd, ..., 99th multiples

⇒ P = {5, 15, 25, ..., 495}

⇒ Average P = (5 + 495) ÷ 2 = 500 ÷ 2 = 250

⇒ Set Q (Even places): 2nd, 4th, ..., 100th multiples

⇒ Q = {10, 20, 30, ..., 500}

⇒ Average Q = (10 + 500) ÷ 2 = 510 ÷ 2 = 255

⇒ Difference = Q − P = 255 − 250 = 5

∴ The correct answer is 5.

Additional Information

Average of Arithmetic Progression

For any sequence in AP, the average is always the middle term or the mean of the first and last terms: (a + l) ÷ 2.

Consecutive Terms Difference

If every term of set B is 'k' more than the corresponding term of set A, then Average(B) − Average(A) = k.

Sum of First n Multiples

Sum of first n multiples of 'x' = x × [n(n+1) ÷ 2]. The average is x × (n+1) ÷ 2.

Question 46

To increase the revenue from the first-class fare, the railways decrease the first-class fare by 30 percent. As a result, the revenue from the first class fare increased by 26 percent. What is the percentage increase in first-class passengers?

  1. AOption (a)

    50 percent

  2. BOption (b)

    80 percent

  3. COption (c)

    100 percent

  4. DOption (d)

    65 percent

View answer & explanation

Correct answer

Answer: (b)B.

80 percent

Why this answer is correct

Given:

To increase the revenue from the first-class fare, the railways decrease the first-class fare by 30 percent.

As a result, the revenue from the first class fare increased by 26 percent.

Concept used:

Revenue = Fare × Number of ticket sold

Calculation:

Let the fare = Rs. 100

Let the initial number of ticket sold/ number of passenger = 100

Initial Revenue = Rs. 100 × 100 = Rs. 10000

Now, 

The decreased fare = (100% - 30%) of Rs. 100 = Rs. 70

Increased revenue = (100% + 26%) of Rs. 10000 = Rs. 12600

Let the number of passengers in new case = x

Now, 

⇒ 70 × x = 12600

⇒ x = 180

The required change (in %) = 180−100100\frac{180-100}{100} × 100 = 80%

Therefore, "80%" is the required answer.

Question 47

A distributed Rs. 2500 among his three friends B, C and D such that B received 40 percent of the amount, C received 60 percent of remaining amount and rest of the amount is received by D. What is the share of D?

  1. AOption (a)

    Rs. 700

  2. BOption (b)

    Rs. 600

  3. COption (c)

    Rs. 500

  4. DOption (d)

    Rs. 400

View answer & explanation

Correct answer

Answer: (b)B.

Rs. 600

Why this answer is correct

Given:

A distributed Rs. 2500 among his three friends B, C and D.

B received 40 percent of the amount,

C received 60 percent of remaining amount,

Rest of the amount is received by D.

Calculation:

According to the question,

Amount received by B = 40% of 2500 = Rs. 1000

Remaining amount = Rs. 2500 - Rs. 1000 = Rs. 1500

Amount received by C = 60% of 1500 = Rs. 900

Remaining amount received by D = Rs. 1500 - Rs. 900 = Rs. 600

Therefore, "Rs. 600" is the required answer.

Question 48

Average cost price of items A and B is Rs. 400. A and B are sold at 10 percent and 20 percent profit respectively and total selling price of A and B is Rs. 918, then find the cost price of item B?

  1. AOption (a)

    Rs. 360

  2. BOption (b)

    Rs. 480

  3. COption (c)

    Rs. 190

  4. DOption (d)

    Rs. 380

View answer & explanation

Correct answer

Answer: (d)D.

Rs. 380

Why this answer is correct

Given:

Average cost price of items A and B is Rs. 400.

A and B are sold at 10 percent and 20 percent profit respectively,

Total selling price of A and B is Rs. 918,

Formula used:

1. Selling price = (100% + Profit%) of Cost price

Calculation:

Let A and B are the cost price of A and B respectively.

According to the question,

Total cost price of A and B = Rs. 400 × 2 = Rs. 800

It can be written as:

⇒ A + B = 800    ---(1)

Selling price of A = (100% + 10%) of A = 1.1A

Selling price of B = (100% + 20%) of B = 1.2B

Now, 

Total selling price = Rs. 918

⇒ 1.1A + 1.2B = 918    ---(2)

On solving (1) and (2), we get,

⇒ B = Rs. 380

Therefore, the cost price of B = Rs. 380

Therefore, "Rs. 380" is the required answer.

Question 49

After selling 17 balls for Rs. 720 the loss is equal to the cost price of 5 balls. What is the cost price of 1 ball?

  1. AOption (a)

    Rs. 45

  2. BOption (b)

    Rs. 50

  3. COption (c)

    Rs. 60

  4. DOption (d)

    Rs. 55

View answer & explanation

Correct answer

Answer: (c)C.

Rs. 60

Why this answer is correct

Given:

After selling 17 balls for Rs. 720 the loss is equal to the cost price of 5 balls.

Calculation:

Let C and S be the cost price and selling price of the ball respectively.

Selling price of 17 balls = 17S

Selling price of 1 ball = 720/17

Cost price of 17 balls = 17C

According to the question,

⇒ 17C - 17S = 5C

⇒ 12C = 17S

⇒ S/C = 12/17

Again according to the question,

⇒ 72017C=1217\frac{\frac{720}{17}}{C} = \frac{12}{17}

⇒ C = Rs. 60

Therefore, "Rs. 60" is the required answer.

Question 50

On a tree, there are some parrots and pigeons in the ratio of 7 ∶ 9. After an hour 8 parrots fly and 6 pigeons and 10 sparrows come on the tree. The ratio of parrots and pigeons now is 1 ∶ 4. Now, what is the ratio of parrots to sparrows?

  1. AOption (a)

    1 ∶ 2

  2. BOption (b)

    3 ∶ 5

  3. COption (c)

    4 ∶ 5

  4. DOption (d)

    1 ∶ 1

View answer & explanation

Correct answer

Answer: (b)B.

3 ∶ 5

Why this answer is correct

Given:

On a tree, there are some parrots and pigeons in the ratio of 7 ∶ 9.

After an hour 8 parrots fly and 6 pigeons and 10 sparrows come on the tree. The ratio of parrots and pigeons now is 1 ∶ 4. 

Calculation:

Case 1:

Number of parrots = 7x

Number of pigeons = 9x

Case 2:

Number of parrots = 7x - 8

Number of pigeons = 9x + 6

Number of sparrows = 10

According to the question,

⇒ (7x - 8)/(9x + 6) = 1/4

⇒ 28x - 32 = 9x + 6

⇒ 19x = 38

⇒ x = 2

Number of parrots in new scenario = 7x - 8 = 6

The ratio of parrot and sparrow = 6 : 10 = 3 : 5

Therefore, "3 : 5" is the required answer.

Question 51

If the ratio of the present age of A to B is 3 ∶ 4 and the ratio of the present age of B to C is 6 ∶ 5. If the present age of C is 20 years, then what is the present age of A?

  1. AOption (a)

    22 years

  2. BOption (b)

    16 years

  3. COption (c)

    20 years

  4. DOption (d)

    18 years

View answer & explanation

Correct answer

Answer: (d)D.

18 years

Why this answer is correct

Shortcut Trick

Combine ratios A : B = 3 : 4 and B : C = 6 : 5 by making B common.

LCM of 4 and 6 is 12.

A : B : C = (3 × 3) : 12 : (5 × 2) = 9 : 12 : 10

C's age = 10 units = 20 years ⇒ 1 unit = 2 years.

A's age = 9 units = 9 × 2 = 18 years.

∴ The correct answer is 18 years.

Alternate Method

Given:

Ratio of present age of A to B = 3 : 4

Ratio of present age of B to C = 6 : 5

Present age of C = 20 years

9 parts A = ? 18

12 parts B 24

10 parts C = 20 20

× 2

× 2

Calculations:

⇒ Let age of B be a common multiple in both ratios.

⇒ LCM of 4 and 6 = 12.

⇒ Multiply A : B by 3 to get B = 12 ⇒ A : B = 9 : 12

⇒ Multiply B : C by 2 to get B = 12 ⇒ B : C = 12 : 10

⇒ Combined ratio of A : B : C = 9 : 12 : 10

⇒ Let the present ages of A, B, and C be 9x, 12x, and 10x respectively.

⇒ We are given present age of C = 20 years.

⇒ 10x = 20 ⇒ x = 2

⇒ Present age of A = 9x = 9 × 2 = 18 years.

∴ The correct answer is 18 years.

Additional Information

Combining Ratios

If a : b = n1 : d1 and b : c = n2 : d2, the combined ratio a : b : c can be found by equalizing the common term 'b'. Multiply the first ratio by n2 and the second ratio by d1, resulting in (n1 × n2) : (d1 × n2) : (d1 × d2).

Age Problems Shortcut

Always relate the exact given numerical value (in years) to its corresponding ratio unit to find the value of 1 ratio part. Multiply this single unit value by the required ratio parts to get the final exact age directly.

Question 52

A certain sum yields Rs. 840 more simple interest if it is invested for two years at 18 percent p.a. than at 12 percent p.a. Find the principal sum. 

  1. AOption (a)

    7000

  2. BOption (b)

    8500

  3. COption (c)

    8000

  4. DOption (d)

    7500

View answer & explanation

Correct answer

Answer: (a)A.

7000

Why this answer is correct

Given:

A certain sum yields Rs. 840 more simple interest if it is invested for two years at 18 percent p.a. than at 12 percent p.a. 

Formula used:

S.I = PRT/100

Where, 

P = Principal sum

R = rate of interest applied 

T = time of investment

Calculation:

According to the question,

⇒ P×18×2100\frac{P \times 18 \times 2}{100} - P×12×2100\frac{P \times 12 \times 2}{100} = 840

⇒ 36P - 24P = 84000

⇒ 12P = 84000

⇒ P = 7000

The principal sum = Rs. 7000

Therefore, "Rs. 7000" is the required answer.

Question 53

If the speed of a train is 72 kmph. then how many kilometers are covered by it in 10 minutes and 35 second?

  1. AOption (a)

    12.7

  2. BOption (b)

    18.2

  3. COption (c)

    15.6

  4. DOption (d)

    17.5

View answer & explanation

Correct answer

Answer: (a)A.

12.7

Why this answer is correct

Given:

The speed of a train is 72 kmph.

Formula:

Distance = Speed × time 

Calculation:

According to the question,

Speed of train = 72 × 5/18 = 20 m/sec

Time required = 10 min 35 sec = 635 sec

Distance = 20 × 635 = 12700 m = 12.7 km

Therefore, "12.7 km" is the required answer.

Question 54

A man travels the first part of his journey at 20 km/h and the next at 70 km/h, covering the entire journey at an average speed of 50 km/h. If he covered 42 km at the rate of 70 km/h, then find the distance covered at 20 km/h?

  1. AOption (a)

    8 km

  2. BOption (b)

    4 km

  3. COption (c)

    6 km

  4. DOption (d)

    3 km

View answer & explanation

Correct answer

Answer: (a)A.

8 km

Why this answer is correct

Given:

A man travels the first part of his journey at 20 km/h and the next at 70 km/h, covering the entire journey at an average speed of 50 km/h.

he covered 42 km at the rate of 70 km/h,

Concept:

  1. Distance = Speed × Time
  2. Average speed = Total distance/ Total time

Calculation:

Case 1:

Distance = 42 km

Speed = 70 km/hr

Time = 42/70 = 0.6 hr

Case 2:

Distance = x km

Speed = 20 km/hr

Time = x/20 hr

Now,

Average speed = (42 + x)/(0.6 + x/20) 

According to the question,

⇒ (42 + x)/(0.6 + x/20) = 50

⇒ 42 + x = 50(0.6 + x/20)

⇒ 42 + x = 30 + 2.5x

⇒ 1.5x = 12

⇒ x = 8

Therefore, "8 km" is the required answer.

Question 55

Eighteen taps can fill a water tank in 20 minutes. How many taps of the same capacity are required to fill up 13\frac{1}{3}rd of the same water tank in 15 minutes?

  1. AOption (a)

    6

  2. BOption (b)

    8

  3. COption (c)

    12

  4. DOption (d)

    9

View answer & explanation

Correct answer

Answer: (b)B.

8

Why this answer is correct

Given:

Eighteen taps can fill a water tank in 20 minutes.

Concept used:

Time taken by A to complete the work = t

Efficiency of A = 1/t

Calculation:

Let the capacity of tank = 1 unit

Time taken by 18 taps to fill a water tank = 20 min

Time taken by 1 tap to fill a water tank = 20 × 18 = 360 min

Efficiency of 1 tap = 1/360 unit per min

Efficiency of x taps = x/360

Required capacity to fill = 1/3

Time required = 15 min

It can be written as:

⇒ 13x360\frac{\frac{1}{3}}{\frac{x}{360}} = 15

⇒ 1/45 = x/360

⇒ x = 8

The number of taps = 8 

Therefore, "8" is the required answer.

Question 56

P, Q, R worked together for 10 days and received Rs. 24000 as wages and they share the wages in the ratio of 5 ∶ 2 ∶ 1 respectively. If P alone does the work, then in how many days he can complete the work?

  1. AOption (a)

    16

  2. BOption (b)

    15

  3. COption (c)

    12

  4. DOption (d)

    18

View answer & explanation

Correct answer

Answer: (a)A.

16

Why this answer is correct

Given:

P, Q, R worked together for 10 days and received Rs. 24000 as wages and they share the wages in the ratio of 5 ∶ 2 ∶ 1 respectively.

Concept:

1. Ratio in which profit distributed = Ratio in which they do work

Since they work for same number of days, 

Therefore, the wages ratio is same as the efficiency ratio.

  1. Total unit of work done by a person = Efficiency of that person × Time taken by that person to that work 

Calculation:

Since they work for same number of days, 

Therefore, the wages ratio is same as the efficiency ratio.

Efficiency of P = 5 units a day

Efficiency of Q = 2 units a day

Efficiency of R = 1 unit a day

Combined efficiency = 5 + 2 + 1 = 8 units a day

Total unit of work = 8 × 10 = 80 units

Number of days required for P to work alone = 80/5 = 16 days

Therefore, "16 days" is the required answer.

Question 57

A person sold ice cream in conical cups such that he filled the cup with the ice cream and made a hemispherical ball with the ice cream above the cup. The radius of both the cup and ball is 7 cm, and the total height of both is 20 cm. What is the volume of an ice cream sold by the person?

  1. AOption (a)

    1496 cm3

  2. BOption (b)

    1146 cm3

  3. COption (c)

    1296 cm3

  4. DOption (d)

    1386 cm3

View answer & explanation

Correct answer

Answer: (d)D.

1386 cm3

Why this answer is correct

Given:

A person sold ice cream in conical cups such that he filled the cup with the ice cream and made a hemispherical ball with the ice cream above the cup.

The radius of both the cup and ball is 7 cm,

The total height of both is 20 cm.

Formula used:

  1. Volume of cone = π/3 × r2 × h
  2. Volume of hemisphere = 2/3 × π × R3

Where, 

r = radius of cone 

R= radius of hemisphere

h = height of the cone

Calculation:

According to the question,

Total height = 20 cm

Height of hemisphere = radius of hemisphere = 7 cm

Therefore, the height of cone = 20 - 7 = 13 cm

Volume of cone = π/3 × 72 × 13 ≈ 667 cm3

Volume of hemisphere =  2/3 × π × 73 ≈ 718 cm3

Total volume = 667 + 719 = 1386 cm3

Therefore, '1386 cm3' is the required answer.

Question 58

The perimeter of a rectangle and a square is 160 cm each. If the difference between their areas is 600 cm2. Find the area of the rectangle.

  1. AOption (a)

    900 cm2

  2. BOption (b)

    1000 cm2

  3. COption (c)

    1200 cm2

  4. DOption (d)

    800 cm2

View answer & explanation

Correct answer

Answer: (b)B.

1000 cm2

Why this answer is correct

Given:

The perimeter of a rectangle and a square is 160 cm each.

The difference between their areas is 600 cm2.

Formula used:

  1. Area of rectangle = length × breadth
  2. Area of square = side2
  3. Perimeter of rectangle = 2(length + breadth)
  4. Perimeter of square = 4 × side

Calculation:

Let S and R be the area of square and area of rectangle respectively.

According to the question,

⇒ 2(l + b) = 160

⇒ l + b = 80

⇒ 4a = 160

⇒ a = 40

Side length of the square = 40 cm

Area of square = 402 = 1600

Now, 

⇒ Required difference in their respective area = 600

⇒ Required difference in their respective area = S - R = 600

⇒ 1600 - R = 600

⇒ R = 1000 cm2

Therefore, "1000 cm2" is the required answer.

Question 59

The given pie-chart represents the distribution of the percentage of sales of a particular brand of car from five showrooms A, B, C, D and E during 2018. The total number of cars sold during that year from the five showrooms is 5000.

What is the total number of cars sold from the showrooms B and D?

  1. AOption (a)

    1450

  2. BOption (b)

    1550

  3. COption (c)

    1650

  4. DOption (d)

    1750

View answer & explanation

Correct answer

Answer: (b)B.

1550

Why this answer is correct

Given:

The given pie-chart represents the distribution of the percentage of sales of a particular brand of car from five showrooms A, B, C, D and E during 2018.

The total number of cars sold during that year from the five showrooms is 5000.

Calculation:

Number of cars sold from company B = 22% of 5000 = 1100

Number of cars sold from company D = 9% of 5000 = 450

Total number of cars sold from company B and D = 1100 + 450 = 1550

Therefore, "1550" is the required answer.

Question 60

The following bar graph shows the number of students placed in six companies from a college in 2021.

If 72 students remained unplaced, then what percent of students placed in HCL from the college in 2021?

  1. AOption (a)

    22 percent

  2. BOption (b)

    20 percent

  3. COption (c)

    12.5 percent

  4. DOption (d)

    15 percent

View answer & explanation

Correct answer

Answer: (d)D.

15 percent

Why this answer is correct

Given:

The following bar graph shows the number of students placed in six companies from a college in 2021.

Calculation:

According to the question:

The total number of students placed = 25 + 41 + 36 + 16 + 22 + 28 = 168

Total number of students from the college = 168 + 72 = 240

The percentage of students from HCL = 36/240 × 100 = 15%

Therefore, "15%" is the required answer.

General English (20 questions)

Question 61

One part of the sentence below may contain an error. Identify the part. If there is no error, choose ‘No error’.

The World Health Organisation's experts says that immunising children against the coronavirus “is not a high priority” given the extremely limited global supply of vaccines.

  1. AOption (a)

    The World Health Organisation's experts says that immunising

  2. BOption (b)

    children against the coronavirus “is not a high priority”

  3. COption (c)

    given the extremely limited global supply of vaccines. 

  4. DOption (d)

    No error. 

View answer & explanation

Correct answer

Answer: (a)A.

The World Health Organisation's experts says that immunising

Why this answer is correct

The correct answer is 'The World Health Organisation's experts says that immunising'

 Key Points

  • The issue in this sentence is subject-verb agreement. The subject, "The World Health Organization's experts," is plural.
  • The correct verb form for the plural subject should be 'say', not 'says'. The verb 'says' is used for singular third-person subjects, such as 'he', 'she', or 'it'.
  • Therefore, the sentence should be "The World Health Organization's experts say that immunising children against the coronavirus “is not a high priority” given the extremely limited global supply of vaccines."

Therefore, the correct answer is Option 1.

Question 62

One part of the sentence below may contain an error. Identify the part. If there is no error, choose ‘No error’.

My father identified the person who has won a beautiful car in the lottery yesterday.

  1. AOption (a)

    My father identified the person 

  2. BOption (b)

    who has won a beautiful car

  3. COption (c)

    in the lottery yesterday. 

  4. DOption (d)

    No error.

View answer & explanation

Correct answer

Answer: (b)B.

who has won a beautiful car

Why this answer is correct

The correct answer is 'who has won a beautiful car'

 Key Points

  • The problem in this sentence is the tense of the verb "has won".
  • The use of "has won" suggests the action is in the recent past and still has relevance to the present.
  • However, the sentence states "in the lottery yesterday", indicating that the event occurred in the past and is complete.
  • The correct form should be "who won a beautiful car" to correctly represent the completed action.

Therefore, the correct answer is Option 2.

Question 63

Select the most appropriate option to substitute the underlined segment in the given sentence. If there is no need to substitute the underlined segment, select ‘No improvement’.

Our meals usually have at least one item make of some kinds of grain.

  1. AOption (a)

    made of some kind

  2. BOption (b)

    making of any kinds

  3. COption (c)

    makes of kind

  4. DOption (d)

    No substitution required 

View answer & explanation

Correct answer

Answer: (a)A.

made of some kind

Why this answer is correct

The correct answer is 'made of some kind'

 Key Points

  • The underlined segment "make of some kinds of grain" is incorrect both in terms of verb form and countability.
  • The verb should be "made" instead of "make" because "meals" is the object that has been made from grain.
  • Additionally, "some kind" is grammatically correct because "grain" is an uncountable noun, so it should be referred to in the singular form, not plural ("kinds").

Therefore, the correct answer is Option 1.

Question 64

Select the most appropriate option to substitute the bracketed part in the given sentence. If there is no need to substitute the bracketed part, select ‘No improvement’.

(As I did not think it was proper to) acquaint her yet with what had happened, I made an excuse.

  1. AOption (a)

    As I did not think it being proper to

  2. BOption (b)

    As I did not think properly to

  3. COption (c)

    As I did not properly think to

  4. DOption (d)

    No Improvement.

View answer & explanation

Correct answer

Answer: (d)D.

No Improvement.

Why this answer is correct

The correct answer is 'No Improvement.'

 Key Points

  • The bracketed part "As I did not think it was proper to" is grammatically correct.
  • It correctly uses the past simple tense, indicating the speaker's previous judgment or consideration about what was proper.
  • The other options provided are less formal or grammatically incorrect.

Therefore, the correct answer is Option 4.

Question 65

Select the most appropriate option to fill in the blank.

Rumours spread that he ______ soon order the army to open fire.

  1. AOption (a)

    will

  2. BOption (b)

    will be

  3. COption (c)

    would be

  4. DOption (d)

    would have

View answer & explanation

Correct answer

Answer: (a)A.

will

Why this answer is correct

The correct answer is 'will'

 Key Points

  • In English grammar, "will" is used to express future actions decided at the moment of speaking or predicting future events.
  • In this case, the sentence talks about a future action, specifically, ordering the army to open fire.
<br>

Therefore, the most appropriate option to fill in the blank is "will".

The completed sentence reads: "Rumours spread that he will soon order the army to open fire."

Additional Information

  • Let's understand why the other options are not appropriate:
  • "will be" - This option is inappropriate as it is used when referring to future actions that have already been planned or are certain to happen. This form often comes with a specific time reference. However, the sentence is about a speculative action (rumored), not a confirmed one, and there's no specific time reference.
  • "would be" - This form is used for hypothetical or possible actions, usually in if-clauses or when reporting speech. Although there's an element of uncertainty in the sentence (rumours), the context doesn't fit the hypothetical nature that would require the use of "would be".
  • "would have" - This form is used to describe unreal or hypothetical actions in the past. It often comes in if-clauses when expressing regrets, or missed opportunities. This sentence is not referring to a past hypothetical situation, so "would have" doesn't fit.

Question 66

Select the most appropriate option to fill in the blanks.

Dharmendra is going ______ the knife next month to try to ______ his knee problems.

  1. AOption (a)

    above, solve

  2. BOption (b)

    under, solving

  3. COption (c)

    above, solved

  4. DOption (d)

    under, solve

View answer & explanation

Correct answer

Answer: (d)D.

under, solve

Why this answer is correct

The correct answer is 'under, solve'

 Key Points

  • The expression "going under the knife" is an idiomatic way to refer to undergoing surgery.
  • "Solve" is used to mean addressing or remedying a problem, in this case, "his knee problems".

Therefore, the correct answer is Option 4.

Question 67

Select the most appropriate option to fill in the blanks.

“It is clear that each of these draft ______ is part of a larger plan that ______ against the ethos and interests of the islands and islanders.

  1. AOption (a)

    regulation, are

  2. BOption (b)

    regulations, is 

  3. COption (c)

    regulations, are

  4. DOption (d)

    regulation, is

View answer & explanation

Correct answer

Answer: (b)B.

regulations, is 

Why this answer is correct

The correct answer is 'regulations, is'

 Key Points

 

  • "regulation, are" - The first part is incorrect because the use of "each" suggests that we are referring to individual elements of a group, thus making "regulation" plural as "regulations". The second part "are" is incorrect because "a larger plan" is singular and thus should take a singular verb "is".
  • "regulations, is" - The first part "regulations" is correct because "each" refers to individual elements of a group, therefore making "regulation" plural. The second part "is" is correct because "a larger plan" is a singular noun phrase and requires a singular verb "is".
  • "regulations, are" - The first part is correct as explained above. However, the second part "are" is incorrect because "a larger plan" is singular and requires a singular verb "is".
  • "regulation, is" - The first part is incorrect because "each" refers to individual elements of a group, thus making "regulation" plural as "regulations". The second part is correct because "a larger plan" is singular and requires a singular verb "is".

Therefore, the most appropriate option to fill in the blanks is 2) "regulations, is".

The completed sentence reads: “It is clear that each of these draft regulations is part of a larger plan that is against the ethos and interests of the islands and islanders."

Question 68

In the following question, there are six sentences marked S1, S6, P, Q, R, and S. The positions of S1 and S6 are fixed. You are required to choose one of the four alternatives which would be the most logical sequence of the sentence in the passage.

S1. Although fruits can no longer grow once picked,

P. taking in oxygen and

Q. they continue to respire for some time,

R. giving off carbon dioxide,

S. just as human beings do

S6. when they breathe.

  1. AOption (a)

    QPRS

  2. BOption (b)

    SQPR

  3. COption (c)

    RPQS

  4. DOption (d)

    PRSQ

View answer & explanation

Correct answer

Answer: (a)A.

QPRS

Why this answer is correct

The correct answer is 'QPRS'

 Key Points

  • Starting with Q establishes the main idea that fruits continue to respire.
  • P and R add more details to this respiration process by explaining it involves taking in oxygen and giving off carbon dioxide.
  • S brings in the comparison to human beings, which is then connected to S6's statement about breathing.

Therefore, the correct answer is Option 1.

Question 69

Select the most appropriate synonym for the given word.

Benevolent

  1. AOption (a)

    Cruel

  2. BOption (b)

    Barbaric

  3. COption (c)

    Gracious

  4. DOption (d)

    Savage

View answer & explanation

Correct answer

Answer: (c)C.

Gracious

Why this answer is correct

The correct answer is 'Gracious'

 Key Points

  • The word 'Benevolent' means well-meaning and kind. It is used to describe someone who is generous and has a disposition to do good.
  • 'Gracious' is a synonym for 'benevolent' as it also describes someone who is courteous, kind, and pleasant, especially towards someone of lower social status.
  • The other options 'Cruel', 'Barbaric', and 'Savage' are not synonyms for 'Benevolent', but rather, they are antonyms.

Therefore, the correct answer is Option 3.

Question 70

Select the most appropriate antonym for the given word.

Squander

  1. AOption (a)

    Confine 

  2. BOption (b)

    Persecute

  3. COption (c)

    Posit

  4. DOption (d)

    Save

View answer & explanation

Correct answer

Answer: (d)D.

Save

Why this answer is correct

The correct answer is 'Save'

 Key Points

  • The word 'Squander' means to waste (something, especially money or time) in a reckless and foolish manner.
  • 'Save' is an antonym for 'Squander' as it means to keep and store up (something, especially money) for future use.
  • The other options 'Confine', 'Persecute', and 'Posit' do not carry meanings that are opposite to 'Squander'.

Therefore, the correct answer is Option 4.

Question 71

Select the INCORRECTLY spelt word. 

  1. AOption (a)

    Canine

  2. BOption (b)

    Compile

  3. COption (c)

    Bolster

  4. DOption (d)

    Coureir

View answer & explanation

Correct answer

Answer: (d)D.

Coureir

Why this answer is correct

The correct answer is 'Coureir'

 Key Points

  • The correct spelling of this word is 'Courier'.
  • 'Canine', 'Compile' and 'Bolster' are all spelled correctly.

Therefore, the correct answer is Option 4.

Question 72

Select the CORRECTLY spelt word.

  1. AOption (a)

    Tropikal

  2. BOption (b)

    Tropical

  3. COption (c)

    Trapical 

  4. DOption (d)

    Tropicol

View answer & explanation

Correct answer

Answer: (b)B.

Tropical

Why this answer is correct

The correct answer is 'Tropical'

 Key Points

  • 'Tropical' is spelled correctly and refers to regions or climates situated in or characteristic of the tropics.
  • 'Tropikal', 'Trapical', and 'Tropicol' are incorrect spellings of 'Tropical'.

Therefore, the correct answer is Option 2.

Question 73

In the following question, out of the four given options, select the one which best expresses the meaning of the idiom/phrase.

Play it by ear.

  1. AOption (a)

    To focus on one thing. 

  2. BOption (b)

    Last try before giving up.

  3. COption (c)

    Act without preparation.

  4. DOption (d)

    A fleeting moment.

View answer & explanation

Correct answer

Answer: (c)C.

Act without preparation.

Why this answer is correct

The correct answer is 'Act without preparation'

 Key Points

  • The idiom 'Play it by ear' originates from music, where it refers to playing music without reference to written notation.
  • In a broader sense, it means to act according to the circumstances, rather than according to a predetermined plan.
  • Example - Since I'm not sure when my last meeting will end, let's play it by ear for our dinner plans
  • The other options do not correctly reflect this meaning.

Therefore, the correct answer is Option 3.

Question 74

In the following question, out of the four given options, select the one which best expresses the meaning of the idiom/phrase.

Get the axe.

  1. AOption (a)

    Lose the job.

  2. BOption (b)

    Examining a group of people and deciding their suitability. 

  3. COption (c)

    Proving the effectiveness of something. 

  4. DOption (d)

    Examining something carefully to not miss out any details. 

View answer & explanation

Correct answer

Answer: (a)A.

Lose the job.

Why this answer is correct

The correct answer is 'Lose the job'

 Key Points

  • The idiom 'Get the axe' is often used to refer to someone losing their job.
  • The 'axe' symbolizes a tool used to cut off something, in this case, employment.
  • The other options do not correctly represent the meaning of the idiom.

Therefore, the correct answer is Option 1.

Question 75

Select the word which means the same as the group of the words given.

One who wants to destroy the government.

  1. AOption (a)

    Vandals

  2. BOption (b)

    Anarchist

  3. COption (c)

    Criminal

  4. DOption (d)

    Amphibian

View answer & explanation

Correct answer

Answer: (b)B.

Anarchist

Why this answer is correct

The correct answer is 'Anarchist'

 Key Points

  • An 'Anarchist' is someone who believes in or tries to bring about anarchy, often seen as seeking to overturn organized government.
  • 'Vandals', 'Criminal', and 'Amphibian' do not carry the same meaning as the given group of words.

Therefore, the correct answer is Option 2.

Read the following passage and answer the questions below.

Arthur Wellesley, 1st Duke of Wellington, KG, GCB, GCH, PC, FRS, was an Anglo-Irish soldier and a Tory statesman who was one of the leading military and political figures of 19th-century Britain, serving twice as the prime minister. He ended the Napoleonic Wars when he defeated Napoleon at the Battle of Waterloo in 1815. 

Wellesley was born in Dublin into the Protestant Ascendancy in Ireland. He was commissioned as an ensign in the British Army in 1787, serving in Ireland as aide-de-camp to two successive lords lieutenant of Ireland. He was also elected as a Member of Parliament in the Irish House of Commons. He was a colonel by 1796 and saw action in the Netherlands and in India, where he fought in the Fourth Anglo-Mysore War at the Battle of Seringapatam. He was appointed governor of Seringapatam and Mysore in 1799 and, as a newly appointed major-general, won a decisive victory over the Maratha Confederacy at the Battle of Assaye in 1803. 

Wellesley rose to prominence as a general during the Peninsular campaign of the Napoleonic Wars and was promoted to the rank of field marshal after leading the allied forces to victory against the French Empire at the Battle of Vitoria in 1813. Following Napoleon's exile in 1814, he served as the ambassador to France and was granted a dukedom. During the Hundred Days in 1815, he commanded the allied army, which, together with a Prussian Army under Blücher, defeated Napoleon at Waterloo. Wellington's battle record is exemplary; he ultimately participated in some 60 battles during his military career. 

Wellington is famous for his adaptive defensive style of warfare, resulting in several victories against numerically superior forces while minimising his losses. He is regarded as one of the greatest defensive commanders of all time, and many of his tactics and battle plans are still studied in military academies around the world. After the end of his active military career, he returned to politics. He was twice British prime minister as a member of the Tory party from 1828 to 1830 and for a little less than a month in 1834.

Question 76

As a newly appointed Major-General, Arthur Wellesley won a decisive victory at ______.

  1. AOption (a)

    Many places in England.

  2. BOption (b)

    Battle of Assaye.

  3. COption (c)

    Battle of Waterloo. 

  4. DOption (d)

    Battle of Seringapatam.

View answer & explanation

Correct answer

Answer: (b)B.

Battle of Assaye.

Why this answer is correct

The correct answer is 'Battle of Assaye'

Key Points

  • The passage clearly mentions, "as a newly appointed major-general, won a decisive victory over the Maratha Confederacy at the Battle of Assaye in 1803."
  • The other options mentioned in the question do not align with the passage details about Wellesley's major-general rank and decisive victory.

Therefore, the correct answer is Option 2.

Question 77

Arthur Wellesley ended the Napoleonic Wars when he defeated Napoleon. Where was Napoleon defeated?

  1. AOption (a)

    Wellington

  2. BOption (b)

    Dublin

  3. COption (c)

    Waterloo

  4. DOption (d)

    Tory

View answer & explanation

Correct answer

Answer: (c)C.

Waterloo

Why this answer is correct

The correct answer is 'Waterloo'

Key Points

  • The text states: "He ended the Napoleonic Wars when he defeated Napoleon at the Battle of Waterloo in 1815."
  • The other options listed, 'Wellington', 'Dublin', and 'Tory', do not match the details provided in the passage about where Napoleon was defeated.

Therefore, the correct answer is Option 3.

Question 78

Which of the following statements is not correct?

  1. AOption (a)

    Wellington is famous for his adaptive defensive style of warfare. 

  2. BOption (b)

    Wellesley rose to prominence as a general during the Peninsular campaign of the Napoleonic Wars

  3. COption (c)

    Following Napoleon's exile, Wellesley served as the ambassador to France.

  4. DOption (d)

    Wellesley had never been a colonel.

View answer & explanation

Correct answer

Answer: (d)D.

Wellesley had never been a colonel.

Why this answer is correct

The correct answer is 'Wellesley had never been a colonel'

Key Points

  • The passage clearly states: "He was a colonel by 1796".
  • The other statements are correct according to the passage.

Therefore, the correct answer is Option 4.

Question 79

What does the word ‘exemplary’ mean in the given passage?

  1. AOption (a)

    Commendable

  2. BOption (b)

    Dishonorable

  3. COption (c)

    Disparaging

  4. DOption (d)

    Lacking

View answer & explanation

Correct answer

Answer: (a)A.

Commendable

Why this answer is correct

The correct answer is 'Commendable'

Key Points

  • The term 'exemplary' in the passage is used to describe Wellington's battle record, meaning it is worthy of imitation; commendable.
  • The other options 'Dishonorable', 'Disparaging', and 'Lacking' do not align with the meaning of 'exemplary'.

Therefore, the correct answer is Option 1.

Question 80

After the end of his active military career, Arthur Wellesley went into ______.

  1. AOption (a)

    Adaptive defensive style of warfare 

  2. BOption (b)

    Politics

  3. COption (c)

    Poetry

  4. DOption (d)

    Training of young soldiers

View answer & explanation

Correct answer

Answer: (b)B.

Politics

Why this answer is correct

The correct answer is 'Politics'

Key Points

  • The passage states: "After the end of his active military career, he returned to politics."
  • The other options 'Adaptive defensive style of warfare', 'Poetry', and 'Training ofyoung soldiers' do not match the details provided in the passage about Arthur Wellesley's career after the military.

Therefore, the correct answer is Option 2.

General Hindi (20 questions)

Question 81

निम्नलिखित में से "कष्टसाध्य" में कौन-सा समास है?

  1. AOption (a)

    तत्पुरुष समास

  2. BOption (b)

    अव्ययीभाव समास

  3. COption (c)

    कर्मधारय समास

  4. DOption (d)

    द्विगु समास

View answer & explanation

Correct answer

Answer: (a)A.

तत्पुरुष समास

Why this answer is correct

उपर्युक्त विकल्पों में से ‘कष्टसाध्य’ में तत्पुरुष समास है। 

Key Points

  • 'कष्टसाध्य' का समास विग्रह ‘कष्ट से साध्य’ होगा।
  • यह करण तत्पुरुष समास का उदाहरण है।

Additional Information

तत्पुरुष समास: जिस समास में उत्तरपद प्रधान हो तथा समास करने के उपरांत विभक्ति(कारक चिन्ह) का लोप हो, तत्पुरुष समास कहलाता है।  जैसे: राम का अनुज= रामानुज, धर्म का ग्रन्थ = धर्मग्रन्थ, तुलसीदास द्वारा कृत = तुलसीदासकृत आदि। तत्पुरुष समास के छः भेद होते हैं-
समासपरिभाषाउदाहरण
कर्म तत्पुरुष समासजहां कर्म कारक चिन्ह (को) का लोप होगिरहकट = गिरह को काटने वाला
करण तत्पुरुष समासजहां करण कारक चिन्ह (से) का लोप होगुणहीन = गुणों से हीन
संप्रदान तत्पुरुष समासजहां संप्रदान कारक चिन्ह (के लिए, को) का लोप होहथकड़ी = हाथ के लिए कड़ी
अपादान तत्पुरुष समासजहां अपादान कारक चिन्ह (से, अलग होने के संबंध में ) का लोप होधनहीन = धन से हीन
संबंध तत्पुरुष समासजहां संबंध कारक (का, की के) का लोप होप्रेम सागर = प्रेम का सागर
अधिकरण तत्पुरुष समासजहां अधिकरण कारक (में , पर) का लोप होनीतिनिपुण = नीति में निपुण

Question 82

निम्नलिखित में से तद्भव शब्द का चयन कीजिए-

  1. AOption (a)

    सुभाग

  2. BOption (b)

    किवाड़

  3. COption (c)

    भिक्षा

  4. DOption (d)

    याचक

View answer & explanation

Correct answer

Answer: (b)B.

किवाड़

Why this answer is correct

दिए गए विकल्पों में से सही उत्तर ‘किवाड़’ है। 

Key Points

  • उपर्युक्त विकल्पों में से 'किवाड़' शब्द तद्भव है।
  • जिसका तत्सम 'कपाट' होता है।
  • अन्य शब्द तत्सम हैं। यथा -
  • सुभाग - सुहाग
  • भिक्षा - भीख
  • याचक - भिक्षुक

Additional Information

शब्दपरिभाषाउदाहरण
तत्समऐसे शब्द जो संस्कृत से ज्यों के त्यों लिए गए, तत्सम होते हैं।कूप, उष्ट्र, पंचम आदि
तद्भवसंस्कृत से हिंदी में आने पर जिन शब्दों का रूप बदल गया हो, तद्भव कहलाते हैं।आग, काम, पाँच आदि।

Question 83

निम्नलिखित में से यौगिक शब्द का चयन कीजिए-

  1. AOption (a)

    कमल

  2. BOption (b)

    धन

  3. COption (c)

    धनवान

  4. DOption (d)

    पुस्तक

View answer & explanation

Correct answer

Answer: (c)C.

धनवान

Why this answer is correct

दिए गए विकल्पों में 'धनवान' यौगिक शब्द का उदाहरण है। 

Key Points

'धनवान' यौगिक शब्द है क्योंकि इसका निर्माण धन+वान (रूढ़+रूढ़) के मेल से हुआ है। 

अन्य विकल्प

शब्दप्रकारकारण
कमलरूढशब्दों का मेल नही
पुस्तकरूढशब्दों का मेल नहीं
धनरूढ़शब्दों का मेल नहीं

Additional Information

रचना के आधार पर शब्दों के तीन भेद माने गए हैं -

शब्दपरिभाषाउदाहरण
रूढ़ शब्दजो शब्द हमेशा किसी विशेष अर्थ को प्रकट करते हो तथा जिनके खण्डों का कोई अर्थ न निकले, उन्हें 'रूढ़' कहते है। इन शब्दों का निर्माण अन्य शब्दों के मेल या संयोग से नहीं होता।'नाक' शब्द  में 'ना' और 'क' का कोई अर्थ नहीं निकल रहा है।
यौगिक शब्दजो शब्द अन्य शब्दों के योग से बने हो तथा जिनके प्रत्येक खण्ड का कोई अर्थ हो, उन्हें यौगिक शब्द कहते है। यह मेल प्रत्यय, उपसर्ग तथा अन्य रूढ़ शब्दों का होता है।डाकघर, पीला - पन, देशवासी आदि।
योगरूढ़ शब्दजो शब्द अन्य शब्दों के योग से बनते हो, परन्तु एक विशेष अर्थ के लिए प्रसिद्ध होते है, उन्हें योगरूढ़ शब्द कहते है। इन शब्दों के सांकेतिक अर्थ होते हैं।पंकज, जलज, लम्बोदर आदि।

Question 84

निम्नलिखित में से कौन-सा वाक्य पूर्वकालिक क्रिया का उदाहरण है?

  1. AOption (a)

    अजय पढ़कर खाता है।

  2. BOption (b)

    अजय, विजय से पत्र लिखवाता है।

  3. COption (c)

    माँ बच्चे को दूध पिलाती है।

  4. DOption (d)

    अजय पढ़ने विद्यालय गया।

View answer & explanation

Correct answer

Answer: (a)A.

अजय पढ़कर खाता है।

Why this answer is correct

सही उत्तर है - अजय पढ़कर खाता है। 

Key Points

  • अजय पढ़कर खाता है। -इस वाक्य में दो क्रियाएं हैं।
  • पढ़ना और खाना।
  • पढ़ना क्रिया पूर्वकालिक क्रिया है क्योंकि यह दूसरी क्रिया के पहले हो रही है।

Important Points

  • पूर्वकालिक क्रिया-
  • पूर्वकालिक का अर्थ होता है– पहले से हुआ।
  • जब कर्ता एक कार्य को समाप्त करके तुरंत दूसरे काम में लग जाता है, तब जो क्रिया पहले ही समाप्त हो जाती है, उसे पूर्वकालिक क्रिया कहते हैं।
  • पूर्वकालिक क्रिया को धातु में कर या करके लगाकर बनाया जाता है।

Question 85

निम्नलिखित में से कौन-सा शब्द "अरण्य" का पर्यायवाची नहीं है?

  1. AOption (a)

    विपिन

  2. BOption (b)

    जंगल

  3. COption (c)

    कानन

  4. DOption (d)

    अनन्य

View answer & explanation

Correct answer

Answer: (d)D.

अनन्य

Why this answer is correct

उपरोक्त विकल्पों में 'अरण्य' का पर्यायवाची शब्द 'अनन्य' नही होता है।

  • अनन्य के पर्���ायवाची - एकनिष्ठ, अद्वितीय, एकमात्र, अभिन्न, अविभक्त, एकाश्रयी, अप्रतिरूप, अद्वितीय, अननुरूप, एकमेव,

Key Points

शब्दपर्यायवाची
अरण्यजंगल, वन, कानन, अटवी, कान्तार, विपिन

Additional Information

शब्दपरिभाषाउदाहरण
पर्यायवाचीएक ही अर्थ में प्रयुक्त होने वाले शब्द जो बनावट में भले ही अलग हों, पर्यायवाची या समानार्थी शब्द कहलाते हैं।आग-अनल, पावक, दहन। हवा-समीर, अनिल, वायु।

Question 86

निम्नलिखित में से शब्द-युग्म के सही अर्थ-भेद का चयन कीजिए-

करण - कर्ण

  1. AOption (a)

    साधन-कान

  2. BOption (b)

    कारण - साधन

  3. COption (c)

    साधन- प्रगति

  4. DOption (d)

    विषय- संसार

View answer & explanation

Correct answer

Answer: (a)A.

साधन-कान

Why this answer is correct

सही उत्तर है - साधन-कान। 

 Key Points

  • करण का अर्थ- साधन
  • कर्ण का अर्थ- कान

Additional Information

शब्दपरिभाषाउदाहरण
समश्रुत शब्दकुछ शब्द ऐसे होते हैं जिनमें स्वर, मात्रा अथवा व्यंजन में थोड़ा-सा अन्तर होता है। वे बोलचाल में लगभग एक जैसे लगते हैं, परन्तु उनके अर्थ में भिन्नता होती है। ऐसे शब्द 'समश्रुत/श्रुतिसम भिन्नार्थक शब्द' कहलाते हैं।जैसे- घन और धन दोनों के उच्चारण में कोई खास अन्तर महसूस नहीं होता परन्तु अर्थ में भिन्नता है। घन-बादल धन-सम्पत्ति

Question 87

निम्नलिखित में से "स्वार्थपरायण" का विलोम शब्द कौन-सा है?

  1. AOption (a)

    मतलबी

  2. BOption (b)

    स्वार्थविमुख

  3. COption (c)

    खुदगर्ज

  4. DOption (d)

    स्वार्थी

View answer & explanation

Correct answer

Answer: (b)B.

स्वार्थविमुख

Why this answer is correct

स्वार्थपरायण शब्द का विलोम शब्द स्वार्थविमुख है।

Key Points

  • स्वार्थपरायण का विलोम स्वार्थविमुख होगा।
  • स्वार्थी का विलोम निस्वार्थी होता है।

Additional Information

शब्दपरिभाषाउदाहरण
विलोम/विपरीतार्थकविपरीत (उल्टा) अर्थ बताने वाले शब्दों को विलोम शब्द कहतेहैं।1. रात - दिन 2. सुख – दुःख

Question 88

दिए गए वाक्यांश के लिए एक शब्द का चयन कीजिए-

सबके साथ मिलकर गाया जानेवाला गान

  1. AOption (a)

    वैमानिक

  2. BOption (b)

    द्विज

  3. COption (c)

    सहगान

  4. DOption (d)

    सुरूप

View answer & explanation

Correct answer

Answer: (c)C.

सहगान

Why this answer is correct

दिए गए विकल्पों में से सही उत्तर ‘सहगान’ है। 

Key Points

  • ‘सबके साथ मिलकर गाया जानेवाला गान’ को सहगान कहा जाता है।

अन्य विकल्प:​

वाक्यांशएक शब्द
विमान संबंधी।वैमानिक
जिनसे दो बार जन्म लिया हो।द्विज
अच्छी आकृतिवाला।सुरूप

Additional Information

वाक्यांशभाषा को सुंदर, आकर्षक और प्रभावशाली बनाने के लिए अनेक शब्दों के स्थान पर एक शब्द का प्रयोग किया जाता है तो वह वाक्यांश के लिए एक शब्द कहलाता है।

Question 89

निम्नलिखित में से कौन-सा वाक्य हेतुहेतुमद भूतकाल का उदाहरण है?

  1. AOption (a)

    कल रात को गौरव आ गया होगा।

  2. BOption (b)

    सम्भवत: वह कल स्कूल जाएगा।

  3. COption (c)

    रोहन अभी खाना खाकर आया है।

  4. DOption (d)

    यदि रोहित ने निमंत्रण दिया होता तो मैं उसकी शादी में अवश्य चलता।

View answer & explanation

Correct answer

Answer: (d)D.

यदि रोहित ने निमंत्रण दिया होता तो मैं उसकी शादी में अवश्य चलता।

Why this answer is correct

सही उत्तर है - यदि रोहित ने निमंत्रण दिया होता तो मैं उसकी शादी में अवश्य चलता।

Key Points

  • हेतुहेतुमद भूतकाल: यह भूतकाल में उस समय को दर्शाती है जहाँ एक क्रिया दूसरी क्रिया पर निर्भर करती है।
  • जैसे: यदि रोहित ने निमंत्रण दिया होता तो मैं उसकी शादी में अवश्य चलता

Important Pointsअन्य विकल्प:-

  • कल रात को गौरव आया होगा। - सम्भाव्य भूतकाल
  • रोहन अभी खाना खाकर आया है।  - आसन्न भूतकाल
  • सम्भवत: वह कल स्कूल जायेगा।  - सम्भाव्य भविष्य काल

Additional Informationभूतकाल के 6 भेद माने गए हैं - 

सामान्य भूतकालक्रिया के समान्य रूप से भूतकाल में पूरा होने का संकेत।सोहन ने गाना गाया।
आसन्न भूतकालक्रिया का अभी- अभी भूतकाल में पूरा होने का संकेत।मैंने खाना खाया है।
पूर्ण भूतकालकार्य को समाप्त हुए बहुत समय बीत चुका है।वह दिल्ली गया था।
अपूर्ण भूतकालकार्य भूतकाल में समाप्त नहीं हुआ है अपितु अभी भी नियमित रूप से जारी है।राम पढ़ रहा था।
संदिग्ध भूतकालअतीत में हुए कार्य पर संदेह प्रकट।तू गया होगा।
हेतुहेतुमद भूतकालपहली क्रिया दूसरी पर निर्भर करती है, कार्य पूर्ण हो सकता था किन्तु दुसरे कार्य की वजह से नहीं हुआ।यदि में आता तो वह चला जाता।

Question 90

निम्नलिखित में से एकवचन शब्द का चयन कीजिए-

  1. AOption (a)

    दाम

  2. BOption (b)

    ओठ

  3. COption (c)

    हरएक

  4. DOption (d)

    होश

View answer & explanation

Correct answer

Answer: (c)C.

हरएक

Why this answer is correct

‘हरएक’ शब्द एकवचन में प्रयुक्त किया जाता है। 

Key Points

  • 'हरएक' शब्द एकवचन में प्रयुक्त होता है। 

दाम, ओठ, होश यह सभी बहुवचन के उदाहरण है।

Additional Information

वचन- संज्ञा के जिस रूप से किसी व्यक्ति और वस्तु के एक या एक से अधिक होने का बोध होता है उसे वचन कहते हैं। जैसे-व्यक्ति-व्यक्तियों, वस्तु-वस्तुएं आदि। वचन दो प्रकार के होते है- 1. एकवचन और 2. बहुवचन।
एकवचनजिस शब्द से किसी वस्तु, व्यक्ति, पदार्थ आदि के एक होने का बोध हो उसे एकवचन कहते है।कमरा, घड़ी, कुत्ता आदि
बहुवचनजिस शब्द से किसी वस्तु, व्यक्ति, पदार्थ आदि के एक से अधिक होने का बोध हो उसे बहुवचन कहते है।कमरे, घड़ियाँ, कुत्ते आदि

Question 91

निम्नलिखित में से मिश्रवाक्य का चयन कीजिए-

  1. AOption (a)

    अपना कार्य पूर्ण करो और घर जाओ।

  2. BOption (b)

    जैसा बोओगे वैसा काटोगे।

  3. COption (c)

    आदित्य या तो स्वयं आएगा या संदेश भेजेगा।

  4. DOption (d)

    जल्दी तैयार हो जाओ, नहीं तो ट्रेन चली जाएगी।

View answer & explanation

Correct answer

Answer: (b)B.

जैसा बोओगे वैसा काटोगे।

Why this answer is correct

दिए गए विकल्पों में से सही उत्तर ‘जैसा बोओगे वैसा काटोगे।’ है। अन्य विकल्प इसके गलत उत्तर हैं। 

Key Points

  • अन्य विकल्प संयुक्त वाक्य के उदाहरण हैं क्योंकि उन सभी में एक प्रधान उपवाक्य और एक आश्रित उपवाक्य है।
  • प्रधान वाक्य - जो उपवाक्य प्रधान या मुख्य उद्देश्य और मुख्य विधेय से बना हो उसे ‘प्रधान उपवाक्य’ कहते हैं।
  • आश्रित उपवाक्य - जो उपवाक्य प्रधान उपवाक्य के आश्रित रहता है, उसे आश्रित उपवाक्य कहते हैं।

Additional Information

रचना की दृष्टि से वाक्य के तीन भेद है:
सरल वाक्यजिस वाक्य में एक क्रिया होती है और एक कर्ता होता है, उसे सरल वाक्य कहते हैं।राजू पानी लाया।
मिश्र वाक्यजिस वाक्य में एक साधारण वाक्य के अतिरिक्त उसके अधीन कोई दूसरा उपवाक्य हो, उसे मिश्र वाक्य कहते हैं।राम उस मकान में रहता है जहां पहले कभी श्याम रहता था।
संयुक्त वाक्यजिस वाक्य में साधारण अथवा मिश्र वाक्यों का मेल संयोजक अवयवों द्वारा होता है, उसे संयुक्त वाक्य कहते हैं।दान करना अच्छी चीज है, दान लेना एक मजबूरी।

Question 92

निम्नलिखित में से अशुद्ध वर्तनी वाले वाक्य का चयन कीजिए-

  1. AOption (a)

    मुकेश का नौकर बिल्कुल कार्य करना नहीं चाहता।

  2. BOption (b)

    मैं उस समय सो रहा था।

  3. COption (c)

    उसे लगभग शत-प्रतीशत अंक मिले।

  4. DOption (d)

    इस पेन्टिंग में मुगलकालीन संस्कृति का चित्रण है।

View answer & explanation

Correct answer

Answer: (c)C.

उसे लगभग शत-प्रतीशत अंक मिले।

Why this answer is correct

इसका सही उत्तर "**उसे लगभग शत-प्रतीशत अंक मिले"**है।

  • अशुद्ध वर्तनी वाला वाक्य है: "उसे लगभग शत-प्रतीशत अंक मिले।" इस वाक्य में 'प्रतीशत' शब्द की वर्तनी गलत है।
  • सही वर्तनी 'प्रतिशत' होनी चाहिए। अतः, सही वाक्य होगा: "उसे लगभग शत-प्रतिशत अंक मिले।"

Key Pointsअन्य विकल्पों का विश्लेषण:

  • मुकेश का नौकर बिल्कुल कार्य करना नहीं चाहता। - यह वाक्य पूरी तरह से ठीक है, 'नौकर', 'बिल्कुल' और 'कार्य' शब्दों की वर्तनी ठीक है।
  • मैं उस समय सो रहा था।" - यह वाक्य भी ठीक है, 'समय', 'सो' और 'रहा' शब्दों की वर्तनी ठीक है।
  • इस पेन्टिंग में मुगलकालीन संस्कृति का चित्रण है। - इस वाक्य में 'पेन्टिंग', 'मुगलकालीन' और 'संस्कृति' शब्दों की वर्तनी सही है।

Question 93

निम्नलिखित में से किस मुहावरे का अर्थ "जैसे को तैसा" है?

  1. AOption (a)

    तुर्की-ब-तुर्की बोलना।

  2. BOption (b)

    तालू में दांत जमना।

  3. COption (c)

    टका-सा जवाब देना।

  4. DOption (d)

    ढंग पर चढ़ना।

View answer & explanation

Correct answer

Answer: (a)A.

तुर्की-ब-तुर्की बोलना।

Why this answer is correct

तुर्की-ब-तुर्की का अर्थ ·۔"जैसे को तैसा"।

  • जब तक हम सभी क्षेत्र में पूर्णतया आत्मनिर्भर नहीं हो जाते हैं तब तक हम इस स्थिति में नहीं हैं कि विरोधियों को तुर्की-ब-तुर्की बोल सकें।

Key Pointsअन्य विकल्पों के अर्थ और वाक्य में प्रयोग नीचे दिए गए हैं:

  • टका-सा जवाब देना - "साफ इंकार करना, कोरा उत्तर देना"। वाक्य प्रयोग - जब मैंने सुरेश से किताब मांगी तो उसने टका सा जवाब दे दिया।
  • तालू में दांत जमना - पूरी तरह से समझना। वाक्य प्रयोग - नीतीश ने सांस्कृतिक मूल्यों का गहराई से अध्ययन किया, अब उसके लिए इसे तालू में दांत जम चुका है।
  • ढंग पर चढ़ना - ठीक होना और संतुलित व्यवहार करना। वाक्य प्रयोग - रामू की अव्यवस्थित लाइफ स्टाइल के बाद अब वह ढंग पर चढ़ गया है।

Question 94

निम्नलिखित में से लोकोक्ति "जस दूल्हा तस बनी बरात" का क्या अर्थ है?

  1. AOption (a)

    जो उपकार करे उसका आहित करना।

  2. BOption (b)

    जितना खर्च करोगे वस्तु उतनी ही अच्छी मिलेगी।

  3. COption (c)

    घर में आने वाले का सत्कार करना चाहिए।

  4. DOption (d)

    जैसा मुखिया वैसे ही अन्य साथी।

View answer & explanation

Correct answer

Answer: (d)D.

जैसा मुखिया वैसे ही अन्य साथी।

Why this answer is correct

जस दूल्हा तस बनी बरात का सही अर्थ है - जैसा मुखिया वैसे ही अन्य साथी।

वाक्य प्रयोग - विवाह में दुल्हा और उसका पिता तो शराब पिये ही थे, उसके साथ आए बराती भी शराब पिए हुए थे जो जस दूल्हा तस बनी बरात वाली कहावत को पूर कर रहें थे।

Key Pointsअन्य विकल्पों का विश्लेषण:

  • जो उपकार करे उसका आहित करना। यह विकल्प ठीक नहीं है। उपयुक्त लोकोक्ति "ईंट का जवाब पत्थर से देना" हो सकती है, जिसका मतलब है कि किसी के बुरे कर्म का समान प्रतिकर्म करना।
  • जितना खर्च करोगे वस्तु उतनी ही अच्छी मिलेगी। यह विकल्प ठीक नहीं है। उपयुक्त लोकोक्ति "जितनी चादर हो उतना ही पाँव पसारो" हो सकती है, जिसका अर्थ है कि जितनी सामर्थ्य हो, उतने ही हिसाब से व्यय करना चाहिए।
  • घर में आने वाले का सत्कार करना चाहिए। यह विकल्प ठीक नहीं है। उपयुक्त लोकोक्ति "अतिथि देवो भवः" हो सकती है, जिसका मतलब है कि घर में आने वाले अतिथियों का सत्कार करना चाहिए।

Question 95

नीचे दिए गए वाक्य में निम्न में से कौन-से चिह्न का प्रयोग किया गया है?

छोटे लोगों का बढ़-चढ़कर बोलना।

  1. AOption (a)

    अल्पविराम चिह्न एवं अर्द्धविराम चिह्न

  2. BOption (b)

    योजक चिह्न एवं पूर्णविराम चिह्न

  3. COption (c)

    अवतरण चिह्न एवं पूर्णविराम चिह्न

  4. DOption (d)

    उद्धरण चिह्न एवं पूर्णविराम चिह्न

View answer & explanation

Correct answer

Answer: (b)B.

योजक चिह्न एवं पूर्णविराम चिह्न

Why this answer is correct

छोटे लोगों का बढ़-चढ़कर बोलना। इस वाक्य में योजक चिह्न एवं पूर्णविराम चिह्न का प्रयोग किया गया है।

Key Points

विराम चिह्न – भाषा के लिखित रूप में विशेष स्थानों पर रुकने का संकेत करने वाले चिह्नों को विराम चिह्न कहते हैं।

विराम चिह्न का नामपरिभाषाउदाहरण
पूर्ण विराम चिह्न (।)जहाँ एक बात पूरी हो जाये या वाक्य समाप्त हो जाये वहाँ पूर्ण विराम ( । ) चिह्न लगाया जाता है।बाजार खुल गया।
अर्द्ध विराम चिह्न (;)जहाँ अल्प विराम से कुछ अधिक ठहरते हैं तथा पूर्ण विराम से कम ठहरते हैं, वहाँ अर्द्ध विराम का चिह्न ( ; ) लगाया जाता है।मुख्य अतिथि आ गए हैं; वह शीघ्र चले जाएंगे।
अल्प विराम चिह्न (,)वाक्य में जहाँ थोड़ा रुकना हो या अधिक वस्तुओं, व्यक्तियों आदि को अलग करना हो वहाँ अल्प विराम (,) चिह्न का प्रयोग किया जाता है।राकेश, मोहन, शीतल और पंकज ने यह चित्र बनाया है।
प्रश्नवाचक चिह्न (?)बातचीत के दौरान जब किसी से कोई बात पूछी जाती है अथवा कोई प्रश्न पूछा जाता है, तब वाक्य के अंत में प्रश्नसूचक-चिह्न का प्रयोग किया जाता है।तुम्हारी माताजी का नाम क्या है ?
विस्मयादिबोधक चिह्न (!)इसका प्रयोग हर्ष, विवाद, विस्मय, घृणा, आश्रर्य, करुणा, भय, संबोधन इत्यादि का बोध कराने के लिए इस चिह्न का प्रयोग किया जाता है।वाह! कितना सुंदर दृश्य है।
लाघव चिह्न (०)किसी बड़े तथा प्रसिद्ध शब्द को संक्षेप में लिखने के लिए उस शब्द का पहला अक्षर लिखकर उसके आगे शून्य (०) लगा देते हैं। यह शून्य ही लाघव-चिह्न कहलाता है।डॉक्टर – डॉ०, प्रोफेसर – प्रो०

निम्नलिखित गद्यांश का ध्यानपूर्वक अध्ययन कर प्रश्नों के उत्तर दीजिए-

कवि- वाणी के प्रसार से हम संसार के सुख-दुख, आनंद क्लेश आदि का शुद्ध स्वार्थमुक्त रूप में अनुभव करते हैं। इस प्रकार के अनुभव के अभ्यास से हृदय का बंधन खुलता है और मनुष्यता की उच्च भूमि की प्राप्ति होती है। किसी अर्थपिशाच कृपण को देखिए। जिसने केवल अर्थलोभ के वशीभूत होकर क्रोध, दया, श्रद्धा, भक्ति आत्माभिमान आदि भावों को एकदम दबा दिया है और संसार के मार्मिक पक्ष से मुंह मोड़ लिया है। न सृष्टि के किसी रूपमाधुर्य को देख वह पैसों का हिसाब-किताब भूल कभी मुग्ध होता है, ना किसी दीन-दुखिया को देख कभी करुणा से द्रवीभूत होता है; ना कोई अपमान सूचक बात सुनकर क्रुद्ध या क्षुब्ध होता है। यदि उससे किसी लोमहर्षक अत्याचार की बात कही जाए तो वह मनुष्य धर्म अनुसार क्रोध या घृणा प्रगट करने के स्थान पर रूखाई के साथ कहेगा कि "जाने दो, हमसे क्या मतलब; चलो अपना काम देखें।" यह महा भयानक मानसिक रोग है। इससे मनुष्य आधा मर जाता है।

Question 96

उपर्युक्त गद्यांश के अनुसार, उदासीनता किस प्रकार का रोग है?

  1. AOption (a)

    मानसिक रोग

  2. BOption (b)

    शारीरिक रोग

  3. COption (c)

    परिवारनियोजन रोग

  4. DOption (d)

    लोमहर्षक रोग

View answer & explanation

Correct answer

Answer: (a)A.

मानसिक रोग

Why this answer is correct

इसका सही उत्तर 'मानसिक रोग' है।

  • उदासीनता इस गद्यांश में एक भयानक मानसिक रोग के रूप में वर्णित की गई है, जिससे व्यक्ति अपनी भावनाओं और दया, करुणा, आदि के प्रति संवेदनशीलता को खो देता है।

Key Pointsअन्य विकल्पों की व्याख्या:

  • शारीरिक रोग: इसे उदासीनता के रूप में नहीं देखा जा सकता है, इसलिए यह उत्तर अनुपयुक्त है।
  • परिवारनियोजन रोग: इसका पाठ्य से कोई संबंध नहीं है, इसलिए यह विकल्प सही नहीं है।
  • लोमहर्षक रोग: इसका अर्थ होता है जो त्वचा में खुजली करता है, जो यहाँ चर्चा में नहीं है, इसलिए यह विकल्प भी सही नहीं है।

Question 97

उपर्युक्त गद्यांश में प्रयुक्त शब्द “कृपण" का क्या अर्थ है।

  1. AOption (a)

    कृतघ्न

  2. BOption (b)

    कंजूस

  3. COption (c)

    एहसानमंद

  4. DOption (d)

    दानी

View answer & explanation

Correct answer

Answer: (b)B.

कंजूस

Why this answer is correct

इस प्रश्न का उत्तर कंजूस है।

  • कृपण शब्द का अर्थ होता है कंजूस या लोभी व्यक्ति जो अपने संपत्ति का अर्थलोभ से ऐसे ही संग्रहित करता है, और उसे दूसरों की सहायता में या दान में नहीं उपयोग करता है।

Key Pointsअन्य विकल्पों की व्याख्या:

  • कृतघ्न: इसका अर्थ हुआ किसी की उपकार की उपेक्षा करनेवाला, जो यहां चर्चा में नहीं है।
  • एहसानमंद: इसका अर्थ हुआ आभारी व्यक्ति, जो "कृपण" के अर्थ से मिलता नहीं।
  • दानी: ऐसा व्यक्ति जो दुसरों की मदद के लिए सहायता या दान करता है, जो "कृपण" का विलोमी होता है।

Question 98

उपर्युक्त गद्यांश के अनुसार, कवि _______ से हम संसार के सुख-दुख, आनंद क्लेश आदि का शुद्ध स्वार्थमुक्त रूप में अनुभव करते हैं।

  1. AOption (a)

    लोभ के प्रसार

  2. BOption (b)

    ज्ञान के प्रसार

  3. COption (c)

    वाणी के प्रसार

  4. DOption (d)

    भय के प्रसार

View answer & explanation

Correct answer

Answer: (c)C.

वाणी के प्रसार

Why this answer is correct

इसका सही उत्तर 'वाणी के प्रसार' है।

  • वाणी के प्रसार" से इसे समझाया जा सकता है कि कवियों की कविताओं और वर्णनों के माध्यम से हम जीवन के विभिन्न पहलुओं, जैसे सुख, दुःख, आनंद, क्लेशादि का अनुभव करते हैं।
  • इस प्रकार, कवियों की वाणी का प्रसार, हमें हमारी जिंदगी और अनुभूतियों को एक गहरे स्तर पर समझने में मदद करता है।

Key Pointsअन्य विकल्पों की व्याख्या:

  • लोभ के प्रसार : यह पसीने नहीं होता है चूंकि लोभ की प्रवृत्तियां सामान्यतः नकारात्मक होती हैं।
  • ज्ञान के प्रसार : हालांकि ज्ञान अवश्य महत्वपूर्ण है, लेकिन यहां कवियों की वाणी की बात की गई है।
  • भय के प्रसार : यह विकल्प भी तब मान्य होता जब कविता भय या आतंक के विषय में होती, लेकिन यहां वह बात नहीं है।

Question 99

उपर्युक्त गद्यांश के संदर्भ में, अत्याचार की बात सुनकर क्या करना चाहिए?

  1. AOption (a)

    दूसरों का ध्यान उधर आकर्षित करना चाहिए।

  2. BOption (b)

    उसकी बात को सुनना ही नहीं चाहिए।

  3. COption (c)

    उसकी बात को नजरअंदाज कर देना चाहिए।

  4. DOption (d)

    उस व्यक्ति से झगड़ा करना चाहिए।

View answer & explanation

Correct answer

Answer: (a)A.

दूसरों का ध्यान उधर आकर्षित करना चाहिए।

Why this answer is correct

सही उत्तर: 'दूसरों का ध्यान उधर आकर्षित करना चाहिए।'

  • यह उत्तर यह सुझाव देता है कि जबरदस्ती या अत्याचार की संदेश या घटना सुनी जाए, तो हमें दूसरों को इसके प्रति जागरुक करने का प्रयास करना चाहिए
  • उनका ध्यान इसमें आकर्षित करना चाहिए, ताकि उनके द्वारा उपाय स्वरूप कदम उठाए जा सकें।

Key Pointsअन्य विकल्प की व्याख्या:

  • उसकी बात को सुनना ही नहीं चाहिए: यह उत्तर सही नहीं है क्योंकि बिना सुने हम कोई समाधान नहीं निकाल सकते।
  • उसकी बात को नजरअंदाज कर देना चाहिए: यह उत्तर अनुचित है क्योंकि अन्याय की सूचना को नजरअंदाज करना मौनी सहमति हो सकती है।
  • उस व्यक्ति से झगड़ा करना चाहिए: यह उत्तर भी गलत है क्योंकि हिंसा या झगड़ा आमतौर पर अधिक हिंसा उत्पन्न करता है।

Question 100

उपर्युक्त गद्यांश में निम्नलिखित में से किस शब्द का प्रयोग नहीं किया गया है?

  1. AOption (a)

    आत्माभिमान

  2. BOption (b)

    रूपमाधुर्य

  3. COption (c)

    अर्थपिशाच

  4. DOption (d)

    कृतज्ञतापूर्ण

View answer & explanation

Correct answer

Answer: (d)D.

कृतज्ञतापूर्ण

Why this answer is correct

इस प्रश्न का सही उत्तर 'कृतज्ञतापूर्ण' है।

  • कृतज्ञतापूर्ण शब्द का उपयोग उपर्युक्त गद्यांश में नहीं किया गया है। इस शब्द का अर्थ होता है किसी के प्रति कृतज्ञता या आभार दिखाने वाला, जो इस पाठ्य में उपस्थित नहीं है।

Key Pointsअन्य विकल्प की व्याख्या:

  • आत्माभिमान: यह शब्द पाठ्य में उपयोग किया गया है।
  • रूपमाधुर्य: यह शब्द भी पाठ्य में उपयोग किया गया है।
  • अर्थपिशाच: पाठ्य में इस शब्द का उपयोग भी किया गया है।

Discipline 1 (20 questions)

Question 101

Which of the following connections generally use series connections?

  1. Household appliances
  2. Small bulb-decorations on Deepawali

Choose the correct code.

  1. AOption (a)

    Neither 1 nor 2

  2. BOption (b)

    Only 1

  3. COption (c)

    Both 1 and 2

  4. DOption (d)

    Only 2

View answer & explanation

Correct answer

Answer: (d)D.

Only 2

Why this answer is correct

Concept:

Resistance: The obstruction offered to the flow of current is known as the resistance. It is denoted by R.

Series Connection: When two or more resistances are connected one after another such that the same current flows through them then it is called resistances in series. The equivalent resistance in series combination is will be

Rser = R1 + R2 + R3

  • Current in each resistor remains same in series connection
  • Voltage is dropped in each resistor
  • Generally used in small bulb decorations.

Parallel Connection: When the terminals of two or more resistances are connected at the same two points and the potential difference across them is equal then it is called resistances in parallel. The net resistance/equivalent resistance(R) of resistances in parallel is given by:

1R=1R1+1R2\frac{1}{R} = \frac{1}{{{R_1}}} + \frac{1}{{{R_2}}}

  • Voltage remains same in each resistor
  • Current divides at each the junction
  • Generally used in house hold appliances because each appliance works only on rated voltage (generally 220 V).

Question 102

In which of the following is concave mirror NOT used?

  1. AOption (a)

    Large mirrors to concentrate sunlight to produce heat in solar furnaces

  2. BOption (b)

    Torches

  3. COption (c)

    Dentists' mirros

  4. DOption (d)

    Side-mirror for trucks

View answer & explanation

Correct answer

Answer: (d)D.

Side-mirror for trucks

Why this answer is correct

Concept:

Concave mirror: The mirror in which the rays converge after falling on it is known as the concave mirror.

  • Concave mirrors are also known as converging mirrors.
  • The focal length of a concave mirror is negative according to the sign convention.

Magnification: In a concave mirror, the magnification is the ratio of the height of the image to the height of the object.

  • When the image is real, the magnification will be negative because the real image is inverted.
  • When the image is virtual, the magnification will be positive because the virtual image is erect.
  • The concave mirror can form a magnified image when the object is kept at a certain distance.
  • A virtual, erect, and magnified image is formed when the object is placed very close (on focal length) to a concave mirror.
  • The dentist uses this mirror to get a magnified view of the teeth. Also used in torches and solar light collectors.

 m=−vum = \frac{-v}{u}

Where m = Magnificent, v = Distance of the image from the mirror, u = Distance of the object from the mirror.

  • Real images are formed by the real intersection of light and are inverted.
  • The virtual image is formed when the light intersection is apparent. Image forma
  • Mirror Formula: The following formula is known as the mirror formula:

1f=1u+1v\frac{1}{f}=\frac{1}{u}+\frac{1}{v}

Where f = Focal length

Additional Information

The image formation by the concave mirror at different locations can be seen in the figure in the form of a ray diagram.

 ​

Question 103

Which of the following is an example of Newton's second law of motion?

  1. AOption (a)

    A person gets hurt when he falls on a cement floor.

  2. BOption (b)

    During swimming we push the water in the backward direction, with our hands and feet, to move in forward direction.

  3. COption (c)

    When a bus stops passengers standing in the bus fall in the forward direction.

  4. DOption (d)

    When a person jumps out of a boat, the boat moves in the opposite direction.

View answer & explanation

Correct answer

Answer: (a)A.

A person gets hurt when he falls on a cement floor.

Why this answer is correct

CONCEPT:

Newton’s Second Law of Motion: The rate of change of linear momentum of a body is directly proportional to the external force applied on the body and this change takes place always in the direction of the applied force.

According to the second law of motion, force

Force∝change;in;momentumtimeForce \propto \frac{{change;in;momentum}}{{time}}

⇒F=Kp2−p1t=Km(v−u)t=Kma⇒ F = K\frac{{{p_2} - {p_1}}}{t} = K\frac{{m\left( {v - u} \right)}}{t} = Kma          [∴v−ut=a]\left[ {\therefore \frac{{v - u}}{t} = a} \right]

Where, K = Constant of proportionality, p = Momentum of the body, m = Mass of the body, u = Initial velocity of the body, v = Final velocity of the body, a = Acceleration of the body.

EXPLANATION:

According to the second law of motion, force

F=m(v−u)tF= \frac{{m\left( {v - u} \right)}}{t}

When a person falls on a cemented floor, his initial velocity(u) is higher than its final velocity (v = 0). So the force will be

F=m(0−u)t=mutF= \frac{{m\left( {0 - u} \right)}}{t} = \frac {mu}{t}

As the velocity of falling down is very large, hence a person gets hurt when he falls on a cement floor.

Additional Information

Newton’s First Law: A body continues to be in its state of rest or of uniform motion along a straight line unless it is acted upon by some external force to change the state.

  • If no net force acts on a body, then the velocity of the body cannot change i.e. the body cannot accelerate.
  • Newton’s first law defines inertia and is rightly called the law of inertia.
  • When a bus stops passengers standing in the bus fall in the forward direction is an example of this law.

Newton’s Third Law:

  • To every action, there is always an equal (in magnitude) and opposite (in direction) reaction.
  • When a body exerts a force on any other body, the second body also exerts an equal and opposite force on the first.
  • Forces in nature always occur in pairs. A single isolated force is not possible.
  • e.g.1 When a person jumps out of a boat, the boat moves in the opposite direction**.**
  • e.g.2 During swimming we push the water in the backward direction, with our hands and feet, to move in forward direction.

Question 104

Which of the following statements is NOT correct about electric current?

  1. AOption (a)

    1 μA = 10-6 A

  2. BOption (b)

    1 C of electric charge is equivalent to the charge contained in nearly 6.25 × 1018 electrons.

  3. COption (c)

    An ammeter needs to be connected in series in an electrical circuit to determine how many amperes of current is flowing in the electric circuit.

  4. DOption (d)

    Current is a vector quantity.

View answer & explanation

Correct answer

Answer: (d)D.

Current is a vector quantity.

Why this answer is correct

Explanation:

Electric Current: The flow of electric charge per unit time is known as electric current

  • If one coulomb of charge crosses an area in one second, then the current thought that area is one Ampere(A)
  • SI unit of current is Ampere (A) or coulomb per second

⇒I=QT⇒ I = \frac{Q}{T}

Where I = Electric current, Q = Electric charge, T = Time

  • 1 μA = 10-6 A
  • Electric current is a scalar quantity
  • Although, Electric current has both magnitude and direction yet it is a scalar quantity. This is because the law of ordinary Algebra is used to add electric current and the law of vector addition is not applicable to the addition of electric.
  • An ammeter needs to be connected in series in an electrical circuit to determine how many amperes of current is flowing in the electric circuit.

​Quantisation of charge: Experimentally it is established that all free charges are integral multiples of a basic unit of charge denoted by e. This basic unit of charge is the charge that an electron or proton carries. Thus charge q on a body is always given by

q = ne

Where n = integer, e = 1.6 × 10-19 C

For 1 C

1 = n × 1.6 × 10-19 

n = 625 × 1016 

n = 6.25 × 1018

Question 105

For persons a, b and c, the images formed in their eye has been depicted below in the diagrams-

Which of the following statements is correct?

  1. Person a needs diverging lens.
  2. Person c suffers from short sightedness.
  3. Person b does not have any vision-problem.
  1. AOption (a)

    1, 2 and 3

  2. BOption (b)

    Only 1 and 3

  3. COption (c)

    Only 2 and 3

  4. DOption (d)

    Only 1 and 2

View answer & explanation

Correct answer

Answer: (b)B.

Only 1 and 3

Why this answer is correct

The correct answer is only 1 and 3

Concept:

Convex Lens:

  • A convex lens is thicker at its center than at its edges. It is also known as a convex lens.
  • When parallel rays of light pass through a converging lens, they bend inward and converge to a point on the other side of the lens. This point is called the focal point.
  • The distance between the lens and the focal point is called the focal length (f).
  • Converging lenses are commonly used in various optical instruments such as cameras, telescopes, and magnifying glasses.

Concave Lens:

  • A Concave lens is thinner at its center than at its edges.
  • When parallel rays of light pass through a diverging lens, they spread out or diverge away from each other.
  • Unlike converging lenses, diverging lenses have a virtual focal point, which is the point from which the diverging rays appear to originate when traced backward.
  • The focal length (f) of a diverging lens is negative.
  • Diverging lenses are commonly used in correcting vision problems such as myopia (nearsightedness).

Explanation:

  • Person a has a condition that requires correction for far-sightedness (hyperopia) or perhaps a condition like presbyopia, where they have difficulty focusing on nearby objects as they age.
  • Person c suffers from hypermetropia, the image formed on the retina is typically blurred for nearby objects due to the focal point of light rays falling behind the retina.

retina.

  • Person b has normal vision and does not require any corrective lenses for refractive errors like myopia or hyperopia. They can see both near and distant objects clearly without any issue.

Thus it implies that Person a needs diverging lens and Person b does not have any vision problem are correct.

Question 106

1 horse power (hp) is approximately equivalent to-

  1. AOption (a)

    725 W

  2. BOption (b)

    772 W

  3. COption (c)

    789 W

  4. DOption (d)

    746 W

View answer & explanation

Correct answer

Answer: (d)D.

746 W

Why this answer is correct

Explanation:

Horsepower: Horsepower is a popular imperial unit of power of an engine. It is defined as the work done by a person or machine per unit amount of time. This term of Horsepower was invented by James Watt.

  • It is a unit of power that compares the power of a machine to the muscle power of the horse.
  • In earlier days it was used to measure steam engine power output was compared to the power of draft horses. But later on, its usage was expanded to different types of piston engines, electric motors, turbines, and other machinery.

One mechanical horsepower of 550 foot-pounds per second is equivalent to 745.7 watts.

⇒ 1 Hp = 550 Foot pound per second

⇒ 1 Pound = 4044822 Newtons

⇒ 1 Foot is 0.3.48 meters

⇒ 1 Hp = 550 × 4.44822 × 0.3048 meters

⇒ 1Hp = 745.69 newton meter per second = 746 watt

Question 107

The image of an object is formed behind a concave mirror, is virtual and is larger in size. where is the object located?

  1. AOption (a)

    at 2F

  2. BOption (b)

    Between F and 2F

  3. COption (c)

    At Principal Focus (F)

  4. DOption (d)

    Between Principal Focus (F) and Pole (P)

View answer & explanation

Correct answer

Answer: (d)D.

Between Principal Focus (F) and Pole (P)

Why this answer is correct

Concept:

Concave mirror: The mirror in which the rays converge after falling on it is known as the concave mirror.

  • Concave mirrors are also known as converging mirrors.
  • The focal length of a concave mirror is negative according to the sign convention.

The image formation by the concave mirror at different locations can be seen in the figure in the form of a ray diagram.

As shown in diagram, when object is placed between F & P, then the image is virtual and is larger in size.

Additional Information

Magnification:  In a concave mirror, the magnification is the ratio of the height of the image to the height of the object.

  • When the image is real, the magnification will be negative because the real image is inverted.
  • When the image is virtual, the magnification will be positive because the virtual image is erect.
  • The concave mirror can form a magnified image when the object is kept at a certain distance.
  • A virtual, erect, and magnified image is formed when the object is placed very close (on focal length) to a concave mirror.
  • The dentist uses this mirror to get a magnified view of the teeth. Also used in torches and solar light collectors.

 m=−vum = \frac{-v}{u}

Where m = Magnificent, v = Distance of the image from the mirror, u = Distance of the object from the mirror.

Important Points

  • Real images are formed by the real intersection of light and are inverted.
  • The virtual image is formed when the light intersection is apparent, and the image formed is erected.
  • Mirror Formula: The following formula is known as the mirror formula:

1f=1u+1v\frac{1}{f}=\frac{1}{u}+\frac{1}{v}

Where f = Focal length

Question 108

Which of the following position-time graphs represent non-uniform motion, where the rate of change in position is decreasing?

  1. AOption (a)

  2. BOption (b)

  3. COption (c)

  4. DOption (d)

View answer & explanation

Correct answer

Answer: (d)D.

Why this answer is correct

Correct option-4

Concept:

INSTANTANEOUS VELOCITY

  • The velocity of a moving object at a particular instant of time is called instantaneous velocity.
  • We can define velocity at a particular instant as the limiting value of average velocity when time interval ∆t approaches zero.
  • Mathematically we can write the same as follows:
  • v=lim⁡Δt→0,ΔxΔtv=\underset{\Delta t\to 0}{\mathop{\lim }},\frac{\Delta x}{\Delta t}
  • When we calculate average velocity or speed the selected time interval can be large or small.
  • But when the time interval selected is infinitesimally small then it is known as instantaneous velocity or speed.
  • For a moving object, the instantaneous speed at any point is equal to the magnitude of instantaneous velocity,
  • but the average speed in a given time interval is always greater or equal to the magnitude of average velocity in that interval.

Explanation:

  • The slope of the position-time graph gives us velocity at a given instant of time.
  • In the case of non-uniform motion, the curve of the position-time graph is not linear or straight.
  • Here, slope in this case given by a tangent to the curve at a particular instant of time.
  • therefore, the position-time graph gives us velocity called instantaneous velocity.

Hence, option-4 is correct.

Question 109

Which of the following types of coal is the best quality of coal?

  1. AOption (a)

    Peat

  2. BOption (b)

    Sub-bituminous

  3. COption (c)

    Lignite

  4. DOption (d)

    Bituminous

View answer & explanation

Correct answer

Answer: (d)D.

Bituminous

Why this answer is correct

Explanation:

Coal: Coal is a sedimentary, organic rock which is flammable.

  • Coal is composed primarily of carbon along with other elements such as hydrogen, sulphur, oxygen, and nitrogen. Coal is mostly used for power generation and metallurgy. ​
  • Higher quality coal produces less smoke, burns longer, and provides more energy than lower quality coal.

Major varieties of coal:

  1. Anthracite- It is the best quality coal. It contains about 80 to 90 percent carbon. It is hard coal. In India, it is mainly found in the district of Reasi in the state of Jammu and Kashmir.
  2. Bituminous- It is the most widely available coal in India. It is of medium quality. It contains about 40 to 75 percent carbon. In India, much of the coal comes under this category.
  3. Lignite- It is of low quality. It is brown in colour. It contains about 30 to 40 percent coal.
  4. Peat- It is the middle stage in the process of coal formation. It contains less than 40 percent carbon. It has more impurities. The parts of the wood are remarkably present in it.

Question 110

A bullet of mass 0.05 kg is fired with a velocity of 120 ms-1 from a rifle of mass 4 kg. What will be the recoil velocity of the rifle?

  1. AOption (a)

    1.5 ms-1

  2. BOption (b)

    1.25 ms-1

  3. COption (c)

    1.75 ms-1

  4. DOption (d)

    1.0 ms-1

View answer & explanation

Correct answer

Answer: (a)A.

1.5 ms-1

Why this answer is correct

Concept:

Law of Conservation of Linear Momentum: If no external force acts on a system (called isolated) of constant mass, the total momentum of the system remains constant with time.

According to the law of conservation of momentum:

m1u1 + m2u2 = m1v1 + m2v2 

Where m1,m2 = Masses of two bodies, u1, u2 = Initial velocities of the bodies, v1, v2 = Final velocities of the bodies

Calculation:

Given:

m1 = 0.05 kg, m2 = 4 kg, u1 = 120 ms-1, u2 = ? 

Total momentum should be conserved,

∴ m1u1 = m2u2 

0.05 × 120 = 4 × u2 

u2 = 1.5 ms-1

Question 111

Which of the following form of energy depends on mass and velocity of an object?

  1. AOption (a)

    Neither Potential nor Kinetic energy

  2. BOption (b)

    Only Potential energy

  3. COption (c)

    Only Kinetic energy

  4. DOption (d)

    Both Potential and Kinetic energy

View answer & explanation

Correct answer

Answer: (c)C.

Only Kinetic energy

Why this answer is correct

Explanation:

Kinetic energy (KE): The energy possessed by a body due to the virtue of its motion is termed as kinetic energy. It is given by

KE=12mv2KE = \frac{1}{2}m{v^2}

Where, m = Mass of the body, v = Velocity of the body, 

Hence, it depends upon mass and velocity of the body.

Potential energy: It is defined as the energy stored due to change in position relative to others, stresses within itself, or many factors. It is given by 

U = m g h 

Where m = Mass of a body, g = Acceleration due to gravity, h = Distance from the ground

Important Points

The sum of potential energy and kinetic energy gives the mechanical energy which is the total energy that is associated with the position and motion of the object.

i.e., M.E = K.E + P.E

Additional Information

The following fig shows different forms of energy

Question 112

Which of the following is an insulator?

  1. AOption (a)

    Aluminum

  2. BOption (b)

    Bakelite

  3. COption (c)

    Silver

  4. DOption (d)

    Copper

View answer & explanation

Correct answer

Answer: (b)B.

Bakelite

Why this answer is correct

Explanation: 

Insulator: An insulator is a material that does not conduct an electrical current.

  • They do not conduct because of the absence of free electrons.
  • The vacuum is also an insulator but is not actually material.
  • Most electrical conductors are covered by insulation.
  • Magnet wire is coated with an extremely thin layer of insulation so that more turns or larger wire may be used in the winding of transformers.
  • The insulator is a material in which the electron does not flow freely.
  • The atom of the insulator has tightly bound electrons.
  • Examples of insulators include plastics, paper, rubber, glass and bakelite, Mica, Porcelain.

Conductor: The conductor is the opposite of the Insulator.

  • A Conductor is an object that allows the free flow of charge.
  • These have free electrons.
  • Examples of conductors include silver, copper, gold, aluminium, iron, graphite.​

Additional Information

  • Pin insulators are used for holding the line conductors on the straight running of poles. These are commonly used in power networks up to 33 kV system.
  • Suspension insulators consist of a number of porcelain discs connected in series by metal links in the form of a string. The conductor is suspended at the bottom end of this string while the other end of the string is secured to the cross- arm of the tower. For high voltage (>33KV), it is a usual practice to use suspension type insulators.

Question 113

A rear-view on an automobile has a radius of curvature of 4.00 m. If a bus is located at 6.00 m from this mirror, then which of the following statements is NOT correct?

  1. AOption (a)

    The image will be formed at a distance of 1.5 m at the back of the mirror.

  2. BOption (b)

    The mirror is convex.

  3. COption (c)

    The image is smaller in size by a factor of 0.20.

  4. DOption (d)

    The image is virtual.

View answer & explanation

Correct answer

Answer: (c)C.

The image is smaller in size by a factor of 0.20.

Why this answer is correct

Concept:

Convex mirrors are used in the rear-view mirrors. Convex mirrors always form a virtual image.

Mirror Formula: The following formula is known as the mirror formula:

1f=1u+1v,\frac{1}{f}=\frac{1}{u}+\frac{1}{v},

Where f = Focal length, v = Distance of the image from the mirror, u = Distance of the object from the mirror.

Also, R = 2f

R = Radius of curvature.

Magnification: In a concave mirror, the magnification is the ratio of the height of the image to the height of the object.

  • When the image is real, the magnification will be negative because the real image is inverted.
  • When the image is virtual, the magnification will be positive because the virtual image is erect.

 m=−vum = \frac{-v}{u}

Where m = Magnificent

Calculation:

Given:

R = 4 m, u = -6 m

Since, R = 2f

f = 4 / 2

f = 2 m

Using 1f=1u+1v\frac{1}{f}=\frac{1}{u}+\frac{1}{v}

12=1−6+1v\frac{1}{2}=\frac{1}{-6}+\frac{1}{v}

v = 1.5 m

Hence, the image will form at a distance of 1.5 m.

Magnification, m=−vum = \frac{-v}{u}

m=−1.5−6m = \frac{-1.5}{-6}

m = 0.25

Hence, the image is smaller by a factor of 0.25.

Question 114

On which of the following does the frictional force depend

  1. Smoothness of the surface
  2. The normal reaction

Choose the correct code.

  1. AOption (a)

    Both 1 and 2

  2. BOption (b)

    Neither 1 nor 2

  3. COption (c)

    Only 2

  4. DOption (d)

    Only 1

View answer & explanation

Correct answer

Answer: (a)A.

Both 1 and 2

Why this answer is correct

CONCEPT:

Frictional Force: 

  • The force exerted between surfaces to resist the relative motion between them is called frictional force.
  • Smooth surfaces have higher frictional force as compared to rough surfaces.
  • So, Frictional force depends upon the surface and opposes the motion.
  • Frictional force helps us while walking.
  • Walking on a smooth surface is difficult due to a lack of friction.
  • Sliding is easy on smooth surfaces compared to rough ones as less friction will ensure proper movement.
  • The frictional force is given as,

F = μN

Where μ = Coefficient of friction, N = Normal reaction force on the surface

EXPLANATION:

  • The frictional force is acting against the direction of an externally applied force so as to impend the motion of the object
  • The frictional force depends on the following factors
  • Nature of the surface
  • Normal reaction​

Additional InformationFrictional forces are of three kinds:-

  • Static friction (fs): When two bodies do not slip on each other, the force of friction is static friction. It can change its value until its max. Fmax ≥ fs
  • Kinetic friction (fk): When two bodies slip over each other the force of friction is called kinetic friction.
  • Rolling friction (fr): Friction caused because of the rolling surface is termed as rolling friction.
  • Rolling friction is less than sliding friction

Question 115

Which of the following exhibits conversion of electric energy into kinetic energy?

  1. AOption (a)

    Table fan

  2. BOption (b)

    Electric bulb

  3. COption (c)

    LED

  4. DOption (d)

    Loudspeaker

View answer & explanation

Correct answer

Answer: (a)A.

Table fan

Why this answer is correct

Explanation:

Kinetic energy (KE): The energy possessed by a body due to the virtue of its motion is termed as kinetic energy. It is given by

KE=12mv2KE = \frac{1}{2}m{v^2}

Where, m = Mass of the body, v = Velocity of the body

Rotational kinetic energy: For a given fixed axis of rotation, the rotational kinetic energy is given by:

 KE=12Iω2KE = \frac{1}{2} Iω^2

Where I = Moment of inertia, ω = Angular velocity.

A fan is an electric appliance which is powered by electric energy. On getting energy, it starts to rotate and hence converts electric energy into kinetic energy.

Additional Information

Potential energy: It is defined as the energy stored due to change in position relative to others, stresses within itself, or many factors. It is given by 

U = m g h 

Where m = Mass of a body, g = Acceleration due to gravity, h = Distance from the ground

Important Points

The sum of potential energy and kinetic energy gives the mechanical energy which is the total energy that is associated with the position and motion of the object.

i.e., M.E = K.E + P.E

The following fig shows different forms of energy

Question 116

Which of the following statements is NOT correct?

  1. The size of an object as perceived by eye depends on its visual angle.
  2. The human eye is most sensitive to yellow-green light having wavelength 5550 Å

Choose the correct code.

  1. AOption (a)

    Neither 1 nor 2

  2. BOption (b)

    Only 2

  3. COption (c)

    Both 1 and 2

  4. DOption (d)

    Only 1

View answer & explanation

Correct answer

Answer: (a)A.

Neither 1 nor 2

Why this answer is correct

Explanation:

Human Eye: The human eye is more or less like a photographic camera.

  • The eyeball is almost spherical in shape having a diameter of about 2.3 cm.
  • The perceived size of an object depends upon
  • Visual angle
  • Distance of object
  • **The most sensitive color to the human eye is yellow-green light having a wavelength 5550 Å.**​

Additional Information

  • The front transparent part of the eye is called the  cornea which serves as the window of the eye for light.
  • Behind the cornea, is a circular diaphragm called iris with a hole in its center. The hole is called the pupil of the eye.
  • The function of the iris is to control and regulate the amount of light entering the eye by adjusting the size of the pupil.
  • When the intensity of light is high, the pupil contracts and vice versa.
  • Behind the pupil, is a double convex lens, called the eye lens.
  • Ciliary muscles adjust the focal length of the eye lens.
  • When the ciliary muscles are relaxed, the eye lens becomes thin. Its focal length increases and converging power decreases.
  • When the ciliary muscles are tense, converging power increases, as focal length decreases.
  • Behind the eye lens, there is a screen called the retina on which an image of the object is formed.
  • In the retina, there are light-sensitive cells in the form of rods and cones.
  • The rod-type cells respond to the intensity of light and cone type cells respond to the colour of light.
  • The image of any object seen persists on the retina for 1/16th of a second, even after the removal of the object, it is called persistence of vision.

Question 117

On which of the following does the value of the voltage or current generated by an AC generator NOT depend?

  1. AOption (a)

    Speed at which the coil or magnetic field rotates

  2. BOption (b)

    The poles of the permanent magnet

  3. COption (c)

    Strength of the field

  4. DOption (d)

    Number of turns in the coil.

View answer & explanation

Correct answer

Answer: (b)B.

The poles of the permanent magnet

Why this answer is correct

Explanation:

AC Generator:

  • An AC generator is a device that converts mechanical energy into electrical energy and generates alternating current.
  • It works on the principle of electromagnetic induction i.e., when a coil is rotated in a uniform magnetic field, an alternating emf is induced in the coil.
  • The main components of the AC generator are:
  1. Armature
  2. Strong field magnet
  3. Slip rings
  4. Brushes
  • When the armature coil ABCD rotates in the magnetic field provided by the strong field magnet, it cuts the magnetic lines of force.
  • Thus the magnetic flux linked with the coil changes and hence induced emf is set up in the coil.
  • The direction of the induced emf or the current in the coil is determined by Fleming’s right-hand rule.
  • The current flows out through the brush B1 in the first half of the revolution and through the brush B2 in the next half revolution of the coil.
  • This process is repeated. Therefore, emf produced is of alternating nature.
  • The coil of the AC generator is rotated with a constant angular speed ω, the angle between the magnetic field vector B and the area vector A of the coil at any instant t is θ. Then,

⇒ θ = ωt

The flux linked with the coil at any time t is,

⇒ ϕ = BA.cos θ

From Faraday’s law, the induced emf at any time t for the rotating coil of N turns is given as,

⇒ ϵ = NBAω. sin(ωt)

If the resistance of the coil is R, then the induced current at any time t for the rotating coil of N turns is given as,

⇒I=ϵR=NBAωsin⁡(ωt)R\Rightarrow I=\frac{\epsilon}{R}=\frac{NBAω \sin(ω t)}{R}

Where, N = No. of turns, B = Magnetic field, A = Area, ω = Angular velocity, R = Resistance of the coil

Hence, current generated depends upon Number of turns in the coil, Strength of the field, Speed at which the coil or magnetic field rotates but not on The poles of the permanent magnet

Question 118

Who out of the following had found out of the accepted value of G or the universal gravitation constant?

  1. AOption (a)

    Henry Cavendish

  2. BOption (b)

    J C Maxwell

  3. COption (c)

    Joseph Priestly

  4. DOption (d)

    Sir Issac Newton

View answer & explanation

Correct answer

Answer: (a)A.

Henry Cavendish

Why this answer is correct

Explanation:

Newton's law of Gravitation: It states that everybody in this universe attracts every other body with a force, which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

The direction of the force is along the line joining the particles. The magnitude of the gravitational force F is given by:

F=GM1M2R2F = G\frac{{{M_1}{M_2}}}{{{R^2}}}

Where G = Universal gravitational constant, M1 = Mass of 1st body, M2 = Mass of 2nd body, R = Distance between the two bodies.

From the above explanation, we can see that,

  • Gravitational constant = 6.67 × 10-11 N m2/kg2
  • G is called the Universal gravitational constant.
  • Accepted value of G is first found out by Henry Cavendish
  • It is the force between two objects which have some mass and distance between them.
  • Sir Issac Newton gave his laws of motion, equations of motion and theory of gravity in his book Principia.

Question 119

Which of the following renewable energy sources can be harnessed all the times?

  1. Solar energy
  2. Wind energy
  3. Geothermal energy

Choose the correct code.

  1. AOption (a)

    Only 2 and 3

  2. BOption (b)

    Only 2

  3. COption (c)

    Only 1

  4. DOption (d)

    Only 3

View answer & explanation

Correct answer

Answer: (d)D.

Only 3

Why this answer is correct

Explanation:

Geothermal Energy: The heat that comes from the earth's subsurface is known as geothermal energy.

  • It can be present in the minerals and fluids underneath the earth's surface, as well as in the hot molten rock known as magma.
  • As it is not dependent on any other factor like sunlight, wind, pressure etc, it can be used all the times.
  • Mile deep wells are drilled into underground lakes to access steam and hot water, which can then be used to power turbines attached to electricity generators.
  • Dry steam, flash, and binary geothermal power plants are the three types of geothermal power plants.
  • The oldest type of geothermal technology is dry steam, which extracts steam from the ground and uses it to directly drive a turbine.
  • Binary plants move hot water into a second liquid with a lower boiling point, which transforms to vapour to drive the turbine,
  • Flash plants use high-pressure hot water into cold, low pressure water

Wind Power: It is generated by the force that wind exerts on the blades of a turbine, causing the turbine's shaft to rotate at a speed of 10 to 20 revolutions per minute (rpm). The rotor shaft is connected to a generator that converts mechanical energy into electrical energy.

  • The amount of energy is generated by a wind turbine depends on:- 1) wind power (main factor) 2) the area swept by the blades 3) air density​
  • A  minimum wind speed (generally 12 -14km/ph) to begin turning and generate electricity.
  • strongly winds (50 - 60 km/hr) to generate at full capacity.
  • As it depends on high velocity winds, it cannot be harnessed all the times.

Solar Energy: It is the energy generated by utilizing energy of the sunlight. To use it we can make solar equipments like solar cooker or can convert it into electricity by using solar panels. It depends on availability of sunlight. Hence it cannot be harnessed all the times.

Question 120

A car travels in a circular motion. Which of the following statements is true?

  1. AOption (a)

    Distance travelled by the car will always be less than displacement of the car.

  2. BOption (b)

    Distance travelled by the car will always be more than displacement of the car.

  3. COption (c)

    Distance travelled by the car will always be equal to displacement of the car.

  4. DOption (d)

    Distance travelled by the car will be zero when displacement is zero.

View answer & explanation

Correct answer

Answer: (b)B.

Distance travelled by the car will always be more than displacement of the car.

Why this answer is correct

Explanation:

Distance: 

  • It is defined as the length of the path traveled by a body.
  • It is a scalar quantity.
  • It cannot be in negative value.
  • It is non-zero in circular motion

​Displacement

  • It is the shortest distance between the initial and final position of the particle.
  • It is a vector quantity.
  • It can be positive, negative and zero.
  • It is zero in circular motion.

When an object moves in a straight line without changing the direction the distance and displacement will be equal in magnitude.

  • When an object changes its direction during the motion its path length will become more compared to the distance between the initial and the final position, so in this case, the magnitude of distance becomes more than the displacement.
  • So the distance will always be more than or equal to displacement.

Discipline 2 (20 questions)

Question 121

Which one of the following element belongs to the third period in the Periodic Table?

  1. AOption (a)

    Be

  2. BOption (b)

    C

  3. COption (c)

    Br

  4. DOption (d)

    Si

View answer & explanation

Correct answer

Answer: (d)D.

Si

Why this answer is correct

Concept:

Periodic Table

  • The periodic table is designed by grouping elements found on earth based on their chemical properties.

  • Elements on same period have same number of shells while elements on same group have same number of valence electrons.

Explanation:

Silicon has an electronic configuration of [Ne] 3s² 3p². 

It has 3 shells and 4 valence electrons. 

It has 3 shells so it is in the 3rd period. 

So, Si is correct option. 

Additional InformationBe and C comes in second period.

Question 122

Which of the following is an example of oxidation reaction in daily life?

  1. Corrosion
  2. Rancidity

Choose the correct code.

  1. AOption (a)

    Both 1 and 2

  2. BOption (b)

    Only 2

  3. COption (c)

    Neither 1 nor 2

  4. DOption (d)

    Only 1

View answer & explanation

Correct answer

Answer: (a)A.

Both 1 and 2

Why this answer is correct

Explanation:

Corrosion

  • When a metal deteriorates due to its reaction with air present in the atmosphere, it can be said as corrosion.
  • The process of corrosion takes place due to oxidation.
  • Iron is rusted and silver is tarnished in the air when they are left free in the air.
  • The metals need to be protected from corrosion.
  • Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture.
  • The beautiful blue-green color (patina) on copper after oxidation is the visible result of the metals losing electrons to the air.

Rancidity

  • Rancidity is the oxidation of fats caused by the biochemical reaction of fats and oxygen.
  • This process leads to the degradation of long-chain fatty acids into small chain compounds and butyric acid which is responsible for rancid taste.
  • It can be prevented by acidic antioxidants as preservatives such as ascorbic acid, tocopherol, BHA etc.

Conclusion:

Both 1 and 2 is the correct option as corrosion and rancidity both require corrosion.

Question 123

Which type of colloid butter is?

  1. AOption (a)

    Aerosol

  2. BOption (b)

    Foam

  3. COption (c)

    Gel

  4. DOption (d)

    Sol

View answer & explanation

Correct answer

Answer: (c)C.

Gel

Why this answer is correct

Explanation:

  • A colloid is a mixture of insoluble suspended particles of the dispersed medium in any dispersion phase.
  • They are commonly known as colloidal solutions.
  • Examples - Shampoos, Perfumes, Paints, etc.

Types of colloid

Dispersed PhaseDispersion MediumType of ColloidExamples
SolidSolidSolid SolSome colored glasses, Gemstones
SolidLiquidSolPaints, Cell fluids
SolidGasAerosolSmoke, Dust
LiquidSolidGelCheese, Butter, jellies
LiquidLiquidEmulsionMilk, Hair Cream
LiquidGasAerosolFog, Mist, Cloud, Insecticide Sprays
GasSolidSolid SolPumice stone, Foam rubber
GasLiquidFoamFroth, Whipped cream, soap lather

Additional Information

  • Colloidal suspension with solid dispersed in a liquid is known as Sol.
  • A gel is a colloidal solution where liquid particles are dispersed in a solid.
  • The liquid in another liquid solution is known as Emulsion.
  • Foam is formed due to the dispersion of many gaseous particles in a liquid or in a solid.
  • Aerosol is the result of solid or liquid dispersion within a gas.
Colloidal SolutionsSize of Particles
Sol0.01-1 nm
Gel270- 334  nm
Emulsion200-100000 nm
Foam163000-400000 nm
Aerosol1000-12000 nm

Question 124

Which of the following statements is NOT correct?

  1. AOption (a)

    Upthrust is not experienced by a body when immersed in a gas.

  2. BOption (b)

    Archimedes Principle can be exhibited even if a body is partially submerged.

  3. COption (c)

    All bodies experience buoyancy when they are immersed in a fluid.

  4. DOption (d)

    Archimedes Principle depends on the density of the fluid.

View answer & explanation

Correct answer

Answer: (a)A.

Upthrust is not experienced by a body when immersed in a gas.

Why this answer is correct

CONCEPT:

  • Archimedes' principle: A body at rest in a fluid is acted upon by a force pushing it upward called the buoyant force, which is equal to the weight of the fluid that the body displaces.
  • ​The buoyant force (FB) is given by,

⇒ Fbuoyant = ρf Vf g 

Where ρf = Density of the fluid in which the object is submerged, Vf = Volume of the displaced fluid (or volume of the object that is submerged inside the fluid)

​EXPLANATION:

  • When an object is submerged in fluid fully or partially there are two forces,
  1. Buoyant force
  2. Weight of the object/Gravitational force
  • Here weight of object (W) = mg = ρo Vo g

Where ρo is the density of the object, Vo is the volume of the object, g is the gravitational acceleration.

Since the upthrust of a body is given by:

Fbuoyant = ρf Vf g 

  • As ρf for gas is very low, therefore upthrust is not experienced by a body when immersed in a gas.
  • From the above equation, it is clear that the upthrust force doesn't depend on the weight of the body.

Question 125

Which of the following elements have an atomic radius of 66 pm?

  1. AOption (a)

    C

  2. BOption (b)

    O

  3. COption (c)

    H

  4. DOption (d)

    N

View answer & explanation

Correct answer

Answer: (b)B.

O

Why this answer is correct

Concept : 

Atomic radius - 

  • The shortest distance between the atom's nuclei and the outermost shell of the atom is called the 'Atomic Radius'.
  • The exact value of the atomic radius of an atom cannot be known.
  • Because the atom is not found in a free state nor can the exact position of the electron be known.​
  • In general, the atomic radius decreases across a period and increases down a group.
  • The atomic radius of these elements is as follows:
C (Carbon)77pm
O (Oxygen)66 pm
H (Hydrogen)53 pm
N (Nitrogen)56 pm

Hence we can conclude that O (Oxygen) has an atomic radius of 66 pm.

Question 126

What is the relation between atmosphere (atm) and Pascal (Pa)? (Where both are the unit of measuring pressure exerted by a gas)

  1. AOption (a)

    1 atm = 1.01 × 106 Pa

  2. BOption (b)

    1 atm = 1.01 × 105 Pa

  3. COption (c)

    1 atm = 1.03 × 106 Pa

  4. DOption (d)

    1 atm = 2.01 × 105 Pa

View answer & explanation

Correct answer

Answer: (b)B.

1 atm = 1.01 × 105 Pa

Why this answer is correct

Explanation:

Pressure: The force per unit area is called pressure. It is denoted by P.

  • The SI unit of pressure is the pascal (Pa).
  • It is a scalar quantity because the pressure acts in all directions at a point inside a gas.
  • The basic formula for pressure is given by:

Pressure(P)=Force(F)Area(A){\rm{Pressure (P)}} = \frac{{{\rm{Force (F)}}}}{{{\rm{Area (A)}}}}

Pressure: The force applied perpendicular to an object's surface by area of the region over which the force is spread is called force.

  • The relation between pascal and atmospheric pressure is given by

⇒ 1 atm =  1.013 x 105 Pa

Important Points

  • 1 bar = 105 pascal

Question 127

Which one of the following is not metalloid?

  1. AOption (a)

    B

  2. BOption (b)

    Te

  3. COption (c)

    Se

  4. DOption (d)

    As

View answer & explanation

Correct answer

Answer: (c)C.

Se

Why this answer is correct

Key Points 

  • Metalloids are the elements that exhibit the property of both metals as well as non-metals.
  • Their properties are intermediate between metals and non-metals.
  • Examples: Boron, Silicon, Tellurium, Polonium, Arsenic, Antimony, and Germanium.

Se or Selenium is not metalloid, so it is the correct option. 

Important PointsIn the periodic table, 

  • The zig zag line separates metals from non - metals.
  • The elements around it (left side of it) are metalloids, left of this are usually metals and right one are non metals.
  • Selenium is non metal.

Question 128

The general range of audible frequencies for human is-

  1. AOption (a)

    24 Hz to 25,000 Hz

  2. BOption (b)

    20 Hz to 20,000 Hz

  3. COption (c)

    26 Hz to 28,000 Hz

  4. DOption (d)

    10 Hz to 25,000 Hz

View answer & explanation

Correct answer

Answer: (b)B.

20 Hz to 20,000 Hz

Why this answer is correct

Explanation:

Sound: A sound is a form of energy that produces the sensation of hearing in our ears.

  • When a source of sound vibrates, it creates a disturbance in the medium. The particles of the medium vibrate in their mean position to transfer this disturbance.
  • So, the particles move forward and backward about their mean position, creating regions of compression and rarefaction.
  • Hence, a sound wave travels in a series of compression and rarefactions.
  • Due to this nature of the transfer of sound energy, sound always requires a medium to propagate.
  • Depending on the frequency of sound waves, they are classified as follows:
Audible sound- This is the type of sound that humans can hear. - It lies in the frequency range of 20 Hz to 20 kHz.
Ultrasonic sound- This is the type of sound with frequencies higher than the audible range of human hearing. - The frequency range of ultrasonic sound is > 20 kHz.
Infrasonic sound- This is the type of sound with frequencies lower than the audible range of human hearing. - The frequency range of infrasonic sound is < 20 Hz.

The particles of a medium move forward and backward to create regions of compression and rarefaction. This is parallel to the direction of the sound wave.

  • Audible sound waves have a frequency range of 20 to 20 kHz.
  • Sound waves require a medium to travel. A vacuum is the absence of matter i.e. there will be no particles present in it to propagate sound. So, the sound does not travel in a vacuum.

Question 129

Manufacturing of which of the following utilizes the Archimedes' Principle?

  1. Submarines
  2. Lactometer

Choose the correct code.

  1. AOption (a)

    Both 1 and 2.

  2. BOption (b)

    Neither 1 nor 2

  3. COption (c)

    Only 1

  4. DOption (d)

    Only 2

View answer & explanation

Correct answer

Answer: (a)A.

Both 1 and 2.

Why this answer is correct

Explanation:

Archimedes principle: It states that a body, when wholly or partially immersed in liquid, experiences an upward thrust which is equal to the volume of the liquid.

  • Archimedes Principle is also known as the physical law of buoyancy.
  • When a solid is fully immersed in a liquid, it loses weight, which is equal to the weight of the liquid it displaces.
  • Apparent weight= actual weight−buoyant force= mg−ρgV
  • Where m = mass of the object and ρ = density of the fluid

 

Archimedes’ principle has many applications.

  • It is used in designing ships and submarines.
  • Lactometers, which are used to determine the purity of a sample of milk, and hydrometers used for determining the density of liquids, are based on this principle.
  • The hydrometer basically consists of a weighted, sealed, long-necked glass bulb immersed in the measured liquid; the flotation depth shows the liquid density, and the neck can be calibrated to read the actual gravity value.
  • A barometer is a scientific instrument that is used to measure air pressure.

Question 130

A sound wave has a frequency of 4 kHz and wave length 40 cm. How long will it take to travel 2.5 km?

  1. AOption (a)

    2.1 seconds

  2. BOption (b)

    4.12 seconds

  3. COption (c)

    3.45 seconds

  4. DOption (d)

    1.56 seconds

View answer & explanation

Correct answer

Answer: (d)D.

1.56 seconds

Why this answer is correct

Concept:

Wave: It can be defined as the transport of energy without the transport of matter.

The properties of waves are:

  • Wavelength (λ): The distance between two crests or troughs of a wave is known as wavelength. One wavelength equals the distance between two consecutive crests.
  • Frequency (f): The number of oscillations or the number of waves passes a given point in one sec. Its SI unit is Hertz.
  • Time period (T): The time taken by the wave to complete one cycle.
  • The relation between velocity, wavelength and frequency and time period of a wave is

⇒f=1T=vλ; ⇒ f = \frac{1}{T} = \frac{v}{λ };

Where f = Frequency, T = Time period, v = Velocity of wave, λ = Wavelength

Time=DistanceSpeedTime = \frac {Distance}{Speed}

Calculation:

Given:

f = 4 kHz = 4 × 103, λ = 40 cm = 0.4 m, D = 2.5 km = 2500 m

Using f=vλ;f = \frac{v}{λ };

4×103=v0.4;4 × 10^3 = \frac{v}{0.4 };

v = 1600 m/s

Now using Time=DistanceSpeedTime = \frac {Distance}{Speed}

Time=25001600Time = \frac {2500}{1600}

T = 1.56 s

Question 131

How can we separate cream from milk?

  1. AOption (a)

    Centrifugation

  2. BOption (b)

    Separating funnel

  3. COption (c)

    Chromatography

  4. DOption (d)

    Filtration

View answer & explanation

Correct answer

Answer: (a)A.

Centrifugation

Why this answer is correct

Explanation:

Centrifugation:

  • In dairies, the process of Centrifugation is used for this process.
  • The milk to be skimmed is put in a closed container in a big centrifuge machine.
  • When the centrifuge machine is switched on, the milk starts rotating at a very high speed in this container.
  • Due to this, the milk separates into ‘cream’ and ‘skimmed milk’.
  • The cream being lighter floats over the skimmed milk and can be removed.

Additional Information

Evaporation- Evaporation is a separation method for homogeneous solutions containing one or more dissolved components. - The liquid solvent components are separated from the solid solute component using this procedure.Separation of sugar from water or salt from water.
Separating funnel- Mostly used to separate two immiscible liquids. - The mechanism relies on the different densities of the particles in the mixture to work. - Due to this difference in densities, layers of the immiscible liquids are formed which can be hence separated.Separation of oil from water.
Distillation- Distillation is done when a mixture contains two or more pure liquids. - A liquid mixture's components are evaporated, condensed, and then segregated here. - When the combination is heated, the volatile component vaporizes first. - The vapor is collected in a liquid state after passing through a condenser.Separation of liquids like alcoholic mixtures.
Filteration- Filtration is the most common method of separating a liquid from an insoluble material. - Consider the combination of sand and water. To remove solid particles from the liquid, filtration is performed. Various filtering agents, such as filtering paper or other materials, are commonly utilized.Separation of sand from water.

Question 132

Which of the following statements is incorrect?

  1. AOption (a)

    Plasma state is used in neon sign bulb.

  2. BOption (b)

    The Sun and the stars glow because of the presence of plasma in them.

  3. COption (c)

    The plasma state consists of super energetic and super excited particles.

  4. DOption (d)

    The plasma is created in stars because of very high pressure.

View answer & explanation

Correct answer

Answer: (d)D.

The plasma is created in stars because of very high pressure.

Why this answer is correct

Explanation:

Plasma:

  • The state of matter which contains the energetic and excited ions and electrons is called as plasma.
  • In stars, plasma is created due to very high temperatures.
  • The Sun and the stars glow because of the presence of plasma in them.
  • The plasma state is used in the neon sign bulb.​
  • In the laboratory, a small amount of gas is heated and ionized by driving an electric current through it, or by shining radio waves into it.
  • Either the thermal capacity of the container is used to keep it from getting hot enough to melt-let alone ionize during a short heating pulse, or the container is actively cooled (for example with water) for longer-pulse operation.
  • Generally, these means of plasma formation give the energy to free electrons in the plasma directly, and then electron-atom collisions liberate more electrons, and the process cascades until the desired degree of ionization is achieved.
  • Sometimes the electrons end up quite a bit hotter than the ions since the electrons carry the electrical current or absorb the radio

Additional Information

There are mainly  four states of matter;

Solid-state:

  • The state of matter in which particles of the matters are tightly packed is called a solid state of matter.
  • For example Ball, pens, books, etc.

Liquid state:

  • The state of matter in which particles are less tightly packed/loosely packed compared to solid-state is called a liquid state.
  • For example water, ghee, oil etc.

Gaseous state:

  • The state of matter in which particles are free to move is called a gaseous state.
  • For example: Air, oxygen etc.

Bose-Einstein condensate:

  • The state of matter in which separate atoms or subatomic particles are cooled down absolute zero temperature is called as Bose-Einstein condensate.
  • Bose-Einstein condensate is latest discovered state of matter

Question 133

X climbs up a small hill in 10 minutes, Y takes only 7 minutes in going up the same hill. The weight of X is equal to the weight of Y and is 54 kg. Which of the following statements is true?

  1. AOption (a)

    Y spends more power than X

  2. BOption (b)

    Y does more work than X

  3. COption (c)

    X does more work than Y

  4. DOption (d)

    X spends more power than Y

View answer & explanation

Correct answer

Answer: (a)A.

Y spends more power than X

Why this answer is correct

Concept:

Power: Power is work done per unit time.

 Power=WorkTimePower = \frac{ Work }{Time}

work done by the force is a product of force acted on body and displacement.

work = force x displacement

force = mass x gravitational acceleration

Calculation:

  • X and Y climbed the same hill therefore displacement is the same for both.
  • Their weight is also the same.
  • therefore work done by X and Y is the same.

The time taken by X and Y to climb the hill is 10 and 7 minutes respectively.

Let, PX and PY are power spent by X and Y respectively.    

PX  = W / 10

PY = W / 7

As denominator of PX is bigger compared to PY.

PX <  PY   

This explains Y spends more power than X.

Additional Information

PHYSICAL QUANTITYSYMBOLUNITSDIMENSIONS
POWERPW[L2 M T-3]
WORKWJ[L2 M T-2]
FORCEFN[L M T-2]

Question 134

Which of the following devices use the multiple reflections of sound?

  1. Stethoscope
  2. Megaphone

Use the correct code.

  1. AOption (a)

    Neither 1 nor 2

  2. BOption (b)

    Both 1 and 2

  3. COption (c)

    Only 1

  4. DOption (d)

    Only 2

View answer & explanation

Correct answer

Answer: (b)B.

Both 1 and 2

Why this answer is correct

Explanation:

Reflection of sound:

  • When sound waves strike a surface, they return back into the same medium. This phenomenon is called the reflection of sound.

Laws of reflection:

  1. The angle of incidence is equal to the angle of reflection.
  2. The incidence wave, the reflected wave, and the normal, all lie in the same plane.

Application of reflection of sound

Stethoscope:

  • The stethoscope is an instrument used by doctors for listening to the sounds produced within the body, especially in the heart and lungs.
  • In the stethoscope, the sound produced within the body of a patient is picked up by a sensitive diaphragm and then travelled through a tube by multiple reflections to reach the doctor's ears.

Megaphones: Megaphones or loudhailers, horns, musical instruments such as trumpets and shehnais, are all designed to send sound in a particular direction without spreading it in all directions.

  • The tube followed by conical opening where sound waves produced goes in forward directions by successive reflections so that amplitude adds up and loudness of sound increases.

Question 135

What is the valency of Lithium?

  1. AOption (a)

    -1

  2. BOption (b)

    0

  3. COption (c)

    2

  4. DOption (d)

    1

View answer & explanation

Correct answer

Answer: (d)D.

1

Why this answer is correct

Valency is the combining power of an element. Elements in the same group of the periodic table have the same valency.

Key Points

  • Valency is the no of electron that looses, shared or gain to achieve stability or we can say to complete it outer most shell.
  • If any element has valence electron (electrons present in outer most shell) less than 4
  • ​​Valency = no of valance electron (valence electron<4)
  • If any element has valence electron ​more than 4
  • ​​Valency = 8 - no of valance electron (valence electron>4)

​For Lithium:

  • Li(Z=3) Electronic configuration = 2, 1
  • Valency = no of valance electron  = 1

​Hence, we can conclude that 1 is the valency of Lithium.

Question 136

Chlorine occurs in nature in two isotopic forms, with masses 35 u and 37 u in the ratio of _______,

  1. AOption (a)

    1 ∶ 2

  2. BOption (b)

    1 ∶ 4

  3. COption (c)

    3 ∶ 1

  4. DOption (d)

    2 ∶ 3

View answer & explanation

Correct answer

Answer: (c)C.

3 ∶ 1

Why this answer is correct

Concept:

  • Isotopes: The atoms which have the same number of protons (or same atomic number) but having different neutrons are called isotopes.
  • Example: 1735Cl and 1737Cl are isotopes of chlorine.
  • The relative abundance of an isotope: The percentage of atoms with a specific atomic mass found in a naturally occurring sample of an element is called a relative abundance of that isotope.

The average mass (M) of an atom of an element is given by:

M = M1 x + M2 (1 - x)

Where M1 is the atomic mass of the first isotope, M2 is the atomic mass of the second isotope, x is the relative abundance of the first isotope, and (1 - x) is the relative abundance of the second isotope.

Calculation:

Given that:

The average mass of chlorine atom (M) = 35.5 u

Let x is the relative abundance of 35 u (M1) and (1 - x) is the relative abundance of 37 u (M2).

Use the formula:

  • M = M1 x + M2 (1 - x)
  • 35.5 = 35 x + 37 (1 - x) = 35 x + 37 - 37 x
    • 2 x = - 1.5
  • = 0.75
  • Ratio = x/(1 - x) = 0.75/(1 - 0.75) = 3: 1

Question 137

What is the mass of a alpha particle?

  1. AOption (a)

    2 u

  2. BOption (b)

    5 u

  3. COption (c)

    3 u

  4. DOption (d)

    4 u

View answer & explanation

Correct answer

Answer: (d)D.

4 u

Why this answer is correct

Concept :

  • An Alpha particle is a positively charged particle.
  • An alpha particle is identical to the nucleus of a helium atom, which consists of two protons and two neutrons.

Explanation:

  • It has a charge of +2e and a mass of 4u.
  • An alpha particle is the same as the nucleus of a Helium atom, with no electrons. Because they are identical to helium nuclei, alpha particles are also sometimes written as He2+ indicating a helium ion with a +2 charge (as it's missing its two electrons).
  • This alpha particle was discovered and named by Ernest Rutherford in 1899.

Hence we can conclude that 4 u is the mass of an alpha particle.

Question 138

Why did Rutherford select gold foil for his experimental?

  1. AOption (a)

    Because he wanted a thin layer as possible.

  2. BOption (b)

    Because he wanted the layer to be as pure as possible.

  3. COption (c)

    Because he wanted a good conductor of electricity.

  4. DOption (d)

    Because he wanted the layer to be made of a heavy element.

View answer & explanation

Correct answer

Answer: (a)A.

Because he wanted a thin layer as possible.

Why this answer is correct

Explanation:

Rutherford’s alpha-particle scattering experiment: This experiment was responsible for the discovery of the atomic nucleus.

  • Ernest Rutherford was interested in knowing how the electrons are arranged within an atom. Rutherford designed an experiment for this.
  • In this experiment, fast-moving alpha (α)-particles were made to fall on a thin gold foil.
  • He selected a gold foil because he wanted as thin a layer as possible. This gold foil was about 1000 atoms thick.
  • α-particles are doubly charged helium ions. Since they have a mass of 4 u, the fast-moving α-particles have a considerable amount of energy.
  • It was expected that α-particles would be deflected by the sub-atomic particles in the gold atoms. Since the α-particles were much heavier than the protons, he did not expect to see large deflections.
  • But, the α-particle scattering experiment gave totally unexpected results. The following observations were made:
  • Most of the fast-moving α-particles passed straight through the gold foil.
  • Some of the α-particles were deflected by the foil by small angles.
  • Surprisingly one out of every 12000 particles appeared to rebound
  • On the basis of his experiment, Rutherford put forward the nuclear model of an atom, which had the following features:
  • There is a positively charged centre in an atom called the nucleus. Nearly all the mass of an atom resides in the nucleus.
  • The electrons revolve around the nucleus in circular paths.
  • The size of the nucleus is very small as compared to the size of the atom.

Additional Information

  • Electron was discovered by J.J. Thomson in 1896.
  • Sir James Chadwick discovered neutrons in the year 1932.
  • The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom (i.e. a proton) is present in the nuclei of all other atoms in the year 1917.

Question 139

In a solution 50 g of sugar is dissolved in 350 g of water. What is the concentration of the solution in terms of mass by mass percentage?

  1. AOption (a)

    9.3 percent

  2. BOption (b)

    7.01 percent

  3. COption (c)

    12.5 percent

  4. DOption (d)

    11.1 percent

View answer & explanation

Correct answer

Answer: (c)C.

12.5 percent

Why this answer is correct

Concept: 

Mass by mass percentage: Mass percent is a way to express a concentration or to describe the component in a specific mixture.

  • The composition of the solution can be represented in a mass percentage that shows the mass of solute present in a given solution quantity.
  • The solute quantity is measured in the mass or by moles.
  • The mass per cent is defined as the grams of solute per gram of solution for a solution, multiplied by 100 to get the percentage.
  • Concentrating a Solution is the amount of solution present in a given quantity (mass or volume) of solution.

Mass % = (mass of solute/mass of solution) x 100

Calculation:

Given:

Solute mass (m) = 50 g, Solvent mass (M) = 350 g

Solution mass = m + M = 50 + 350

Solution mass = 400 g

Mass % = (mass of solute/mass of solution) x 100

Mass % = (50 / 400) × 100

Mass % = 12.5 %

Question 140

The velocity of sound will be highest in-

  1. AOption (a)

    Water

  2. BOption (b)

    Silver

  3. COption (c)

    Gas

  4. DOption (d)

    Steel

View answer & explanation

Correct answer

Answer: (d)D.

Steel

Why this answer is correct

Explanation: 

Sound is a mechanical wave that needs a medium to travel.

  • The speed of sound is maximum in solid, then it is in liquid and it is the slowest in gases.
  • The speed of sound remains almost the same for all frequencies in a given medium under the same physical conditions.
  • The speed of the sound depends on the density of the medium through which it is travelling.
  • The particles in the solid medium are closely packed. Hence, the density is high. Information from one molecule to another molecule travels faster in the solid medium.
  • The velocity of sound is highest in steel.
  • In liquid, the molecules are farther apart than in solids. Hence, the density is low for liquids.
  • In gas, the molecules are very loosely dispersed. The speed of the sound wave will be maximum in steel.

Additional Information

  • The velocity of sound waves in air is 330 m/s.
  • The velocity of sound waves in steel is 5920 m/s.
  • The velocity of sound waves in a vacuum is zero.
  • The velocity of sound waves in water is 1480 m/s.

Discipline 3 (20 questions)

Question 141

How does the colour of silver chloride change in sunlight?

  1. AOption (a)

    Grey to white

  2. BOption (b)

    Green to white

  3. COption (c)

    White to grey

  4. DOption (d)

    White to Green

View answer & explanation

Correct answer

Answer: (c)C.

White to grey

Why this answer is correct

Explanation:

Silver halides: 

  • A silver halide (also known as a silver salt) is a chemical compound formed when the element silver (Ag) reacts with one of the halogens.
  • Bromine (Br), chlorine (Cl), iodine (I), and fluorine (F) can all mix with silver to produce silver bromide (AgBr), silver chloride (AgCl), silver iodide (AgI), and three different types of silver fluoride.
  • They're known as the silver halides as a group, and they're typically denoted by AgX.
  • Although the majority of silver halides contain silver atoms with oxidation states of +1 (Ag+), silver halides with oxidation states of +2 (Ag2+) are also known,
  • Silver (II) fluoride is the only one that is stable where Ag is in a +2 oxidation state.
  • Silver halides are Light-sensitive compounds.
  • Silver chloride is turns grey from white when exposed to sunlight.
  • They are widely employed in photographic film and paper.
  • Silver halide crystals in gelatin are coated onto a film base, glass, or paper substrate in photographic film and photographic paper, including graphic art film and paper.
  • As a protective colloid with adequate physical and chemical properties, gelatin is an essential component of the emulsion.
  • Although modern practice employs gelatin without trace materials (such as sulphur), the gelatin may contain trace elements (such as sulphur) that boost the emulsion's light sensitivity.

Additional InformationColour intensity of silver halides:  

  • Silver halides, except for silver fluoride, are extremely water-insoluble.
  • The three most common silver halide compounds have different colours that can be used to identify halide ions in a solution fast.
  • Silver chloride precipitates as a white substance.
  • silver bromide is a creamy substance.
  • Silver iodide is a yellow substance.
  • AgI being yellow when it precipitates has greater colour intensity whereas AgCl being white appears to be dull and least colour intensive.

The correct order of silver halides on the basis of colour intensity is - AgCl < AgBr < Agl

Question 142

In the formula of Hexane how many hydrogen atoms are present?

  1. AOption (a)

    14

  2. BOption (b)

    12

  3. COption (c)

    10

  4. DOption (d)

    16

View answer & explanation

Correct answer

Answer: (a)A.

14

Why this answer is correct

Concept:

Alkanes are hydrocarbons having only a single bond Carbon Carbon linkage across the compound. 

The general formula for alkanes is CnH2n + 2. 

Explanation:

In hexane, there are 6 carbon atoms. 

So, n = 2

Number of hydrogen atoms is 

2n + 2 = 2 (6) + 2 = 12 + 2 = 14

Sp the correct option is 14

Additional InformationAlkene has one double bond Carbon Carbon linkage. The formula is Cn H 2n

Alkyne has one triple bond Carbon Carbon linkage. The formula is Cn H 2n - 2.

Question 143

Graver's disease causes due to hyper secretion of _______ hormone.

  1. AOption (a)

    Aldosterone

  2. BOption (b)

    Thyroid hormone

  3. COption (c)

    ACTH

  4. DOption (d)

    Insulin

View answer & explanation

Correct answer

Answer: (b)B.

Thyroid hormone

Why this answer is correct

Explanation:

The correct answer is Thyroid hormone.

Thyroid gland & its hormone : 

  • Thyroid hormone is secreted by Thyroid gland (small butterfly-shaped gland) located in your throat.
  • Role of the Thyroid gland: This gland plays a major role in - metabolism, growth and development.

Grave's disease (also known as Basedow's disease) : 

  • It is an immune system-related disorder in which the thyroid gland overproduces thyroid hormone than your body needs (hyperthyroidism).
  • Robert James Grave, an Irish doctor was the first to describe this disease.
  • A person suffering from Grave's disease, his/her immune system instead of producing antibodies to target a specific invader, mistakenly produces different antibodies that target their own healthy thyroid cells.

Hormones mentioned & their functions : 

HormoneGlandFunction
AldosteroneSecreted by the adrenal gland (located on top of the kidneys)Helps to regulate blood volume and blood pressure.
ACTH (AdrenoCorticoTropic Hormone)Secreted by the pituitary gland (located in the brain)Helps to regulate blood volume and blood pressure. - plays a major role in how your body responds to stress
InsulinSecreted by the pancreas gland (located behind your stomach and in front of your spine)Helps to control glucose levels in our blood.

Question 144

Aqua regia is a freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of _______.

  1. AOption (a)

    3 ∶ 2

  2. BOption (b)

    3 ∶ 1

  3. COption (c)

    1 ∶ 3

  4. DOption (d)

    2 ∶ 3

View answer & explanation

Correct answer

Answer: (b)B.

3 ∶ 1

Why this answer is correct

The correct answer is 3:1.

  • Aqua regia is a yellow-orange or sometimes red color fuming liquid.
  • Aqua regia is made by combining one part concentrated nitric acid (HNO3 ) to three parts concentrated hydrochloric acid (HCl).
  • It must be made fresh because it will decompose quickly.

Additional Information

  • Uses:
  • ​It is used for the manufacture of chloroauric acid.
  • It can dissolve noble metals such as gold and platinum but not all metals.
  • It is used as an electrolyte in the Wohlwill process to refine gold of the highest quality.

Question 145

Which one of the following does not react with dilute HCL?

  1. AOption (a)

    Zn

  2. BOption (b)

    Al

  3. COption (c)

    Fe

  4. DOption (d)

    Cu

View answer & explanation

Correct answer

Answer: (d)D.

Cu

Why this answer is correct

Explanation:

  • The electrochemical series defines the order of metals according to their reactivity.
  • It moves downwards with decreasing rate of reactivity.
  • Hence, the topmost metal shows the highest reactivity and the lowermost metal shows the least reactivity.
  • The electrochemical series is also called the activity series

Displacement Reactions: 

  • A displacement reaction is a type of reaction that occurs when an atom or a set of atoms in a molecule is replaced by another atom.
  • **The displacement of one by another is only possible when the one displacing is more reactive than the one being displaced.**​

For Example:

2 HCl + 2 Na → H2 + 2 NaCl

2 HCl + 2 K → H2 + 2 KCl

2 HCl + Ca → H2 + CaCl2

HCl + Cu → No Reaction

As Cu comes after Hydrogen in reactivity series. Hence it cannot replace hydrogen. Rest all three - sodium (Na), potassium (K) and calcium (Ca) will produce hydrogen gas as they are more reactive. 

Additional Information

  • When an iron nail is kept in a copper sulphate blue colour solution, the bluish colour of the copper sulphate solution fades and the iron nail becomes brownish in colour.
  • This is because, when we look at the reactivity series, we can see that iron is more reactive than copper and hence it displaces copper from its solution and forms iron sulphate
  • In this reaction, iron has displaced or removed another element, copper, from the copper sulphate solution. This reaction is known as the displacement reaction.

Fe (s) + CuSO4 (aq) → FeSO4 (aq) + Cu (s)

Question 146

Which of the following is a mixture of chloroxylenol and terpineol?

  1. AOption (a)

    Furacine

  2. BOption (b)

    Iodoform

  3. COption (c)

    Soframicine

  4. DOption (d)

    Dettol

View answer & explanation

Correct answer

Answer: (d)D.

Dettol

Why this answer is correct

Explanation:

  • Dettol is an antiseptic solution that is easy to be found in the commercial market.
  • Dettol is the mixture of isopropanol, castor oil, chloroxylenol, soap, Terpineol,  pine oil, and water.

Uses -

Dettol is used as an antiseptic and disinfectant in the domestic and commercial market.

Important Points

  1. Furacine-   It is mainly made up of Nitrofurazone which is a kind of Nitrofuran compound. Furacine is used for its antimicrobial properties.
  2. Iodoform -  The chemical name of iodoform is Tri-iodomethane. It was used earlier as an antiseptic but the antiseptic properties are due to the liberation of iodine. It has an objectional smell too.
  3. Soframicine -  It is aminoglycoside-based antibiotic skin cream. It is used to treat wounds,  skin burns, ulcers, etc.

Question 147

Which gas is produced when alcohols react with sodium?

  1. AOption (a)

    H2

  2. BOption (b)

    CO2

  3. COption (c)

    O2

  4. DOption (d)

    NH3

View answer & explanation

Correct answer

Answer: (a)A.

H2

Why this answer is correct

Explanation:

  • Alcohols react with sodium leading to the evolution of hydrogen.

e.g. 2Na + 2CH3CH2OH 🡪 2CH3CH2O–Na (Sodium ethoxide) + H2 (g)

  • In the reaction of alcohols with sodium metal, bond cleavage of the O - H bond takes place.
  • The ease of breakage of the O-H bond in alcohols is an indication of the acidity of alcohols.

We know that the ease of this bond breakage follows the order primary > secondary > tertiary.

So, the ease of reactivity of sodium follow the order

 

Additional InformationThe acidity of alcohols:

  • Just as metals react with acids to liberate hydrogen, alcohols react with metals to liberate hydrogen acting as an acid.
  • The conjugate base alkoxide ion formed after alcohol releases a proton is R -O -.
  • The stability of the conjugate base depends on the +I of the alkyl group R attached because it is not resonance stabilized here.
  • The strength of negative charge increases as we move on from primary to secondary to tertiary alcohols because of the number of alkyl groups increases.
  • The increase in negative charge over the oxygen atom destabilizes the conjugate base.
  • Thus, the acidity of alcohols follows the order Primary> Secondary > Tertiary.

Question 148

Which one of the following is an oxidizing agent?

A. Alkaline KMnO4

B. Acidified K2Cr2O7

  1. AOption (a)

    Only B

  2. BOption (b)

    Neither A nor B

  3. COption (c)

    Both A and B

  4. DOption (d)

    Only A

View answer & explanation

Correct answer

Answer: (c)C.

Both A and B

Why this answer is correct

Concept:

  • Oxidizing agent: The element, atom, or ion is reduced in a redox reaction or oxidizes other elements, atoms, or ions in a chemical reaction. The oxidizing agent is also known as Oxidant.
  • Oxidation: The chemical reaction in which oxygen is added to the reactants or Hydrogen is removed from the reactants or In which there is a loss of electron is said to be an Oxidation Reaction.

Reduction:

  • The chemical reaction in which hydrogen is added to the reactants or Oxygen is removed from the reactants or In which there is a gain of an electron is an aid to be Reduction Reaction.
  • Redox: A reaction where Oxidation and Reduction both take place simultaneously at a time.

Zn  +  CuSO4  → ZnSO4 +  Cu

Here,  zinc is oxidized to Zinc sulfate and copper sulfate acts as an oxidizing agent.

Explanation:

  • The maximum oxidation state for potassium permpermanganate is +7, thus they act as a good oxidizing agent.
  • Potassium dichromate is highly electronegative in nature thus they behave as good oxidizing agents.

Question 149

What is the pH range of our body?

  1. AOption (a)

    5.7 - 6.5

  2. BOption (b)

    7.0 - 7.8

  3. COption (c)

    8.1 - 9.0

  4. DOption (d)

    6.1 - 7.0

View answer & explanation

Correct answer

Answer: (b)B.

7.0 - 7.8

Why this answer is correct

Explanation:

The pH range of a human body is 7.35 - 7.45.

The closest answer is 7.0 - 7.8

  • pH means the potential of Hydrogen.
  • The pH scale is the scale used to express the acidity or alkalinity of a substance based on the concentration of hydrogen ions in its solution.
  • pH scale was discovered by Soren Sorensen.
  • The range of pH scale 0 to 14.
  • If pH < 7 then solution is acidic.
  • If pH > 7 then solution is basic.
  • If pH = 7 then solution is neutral
  • The strength of acids and bases depends on the number of H+ ions and OH- ions produced, respectively.
  • When the pH of rainwater is less than 5.6, it is called acid rain.
  • The pH value of the Milk of Magnesia is 10.5.

Question 150

_______ is a single cell organism.

  1. AOption (a)

    Nermatodes

  2. BOption (b)

    Acanthocephalans

  3. COption (c)

    Amoeba

  4. DOption (d)

    Platyhelminthes

View answer & explanation

Correct answer

Answer: (c)C.

Amoeba

Why this answer is correct

Explanation:

  • An amoeba often known as amoeboid is a microscopic single cell organism found in pond water.
  • Amoeba has a cell membrane, a rounded, dense nucleus, and many small bubble-like vacuoles in its cytoplasm.
  • Amoeba constantly changes its shape and position.
  • It pushes out one, or more finger-like projections, called pseudopodia or false feet for movement and capture of food.
  • Amoeba feeds on some microscopic organisms.
  • When it senses food, it pushes out pseudopodia around the food particle and engulfs it.

Additional Information

  • Nermatodes
  • Nematodes are a group of lesser-known but the most abundant group of multicellular organisms on earth.
  • They can be defined as a group of thread/worm-like, transparent, bilaterally symmetrical, pseudocoelomate and multicellular organisms that are free-living or parasitic to plants or animals
  • Acanthocephalans
  • Acanthocephalans is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host.
  • These are multicellular organism.
  • Platyhelminthes
  • Members of the phylum Platyhelminthes are worms that lack a body cavity and have an incomplete digestive system are multicellular.

Question 151

Which of the following layers of atmosphere is the closest to the earth?

  1. AOption (a)

    Mesosphere

  2. BOption (b)

    Troposphere

  3. COption (c)

    Stratosphere

  4. DOption (d)

    Thermosphere

View answer & explanation

Correct answer

Answer: (b)B.

Troposphere

Why this answer is correct

Explanation:

 

The following figure shows the different layers of the atmosphere.

Troposphere characteristics:

  • The word troposphere is derived from the Greek word ‘tropo’, meaning turbulence. This layer subjects intense mixing due to both horizontal and vertical turbulence.
  • This the lowermost layer of the atmosphere and is important because all weathering actions (fog, cloud, due frost, cloud thunder, lightning, etc) takes place in this layer.
  • This layer reaches up to 7 km above from the sea level at the poles and up to 17 km above from the sea level at the equator.
  • The upper limit of the troposphere is called the tropopause.

Additional Information

The characteristics for different layers of atmosphere are given below in tabulated form:

Layer of AtmosphereCharacteristics
Troposphere1. All weather phenomena like clouds, Rain, snow etc occurred here, due to which aircrafts does not fly in this region. 2. Temperature decreases with increase in Height, by about 6.5°C per kilometre. 3. Pressure also decreases with increase in height. 4. Speed of sound is directly proportional to temperature, which means that it decreases with increase in height.
Stratosphere1. Temperature increases with increase in height. 2. Ozone layer is present which absorbs the harmful UV rays from sun.
Mesosphere1. The temperature again decreases with height, reaching a minimum of about -90°C.
Thermosphere1. Temperature increases with height. 2. A thin layer called ionosphere is present in which energetic solar radiation knock out electrons off molecules and atoms, turning them into "ions" with a positive charge.
Exosphere1. Outermost layer of atmosphere. 2. It contains mainly oxygen and Hydrogen which are separated by very large distance and due to which they never collide with each other.

Question 152

What is the sweetness value of Saccharin in comparison to cane sugar?

  1. AOption (a)

    550

  2. BOption (b)

    2000

  3. COption (c)

    100

  4. DOption (d)

    600

View answer & explanation

Correct answer

Answer: (a)A.

550

Why this answer is correct

The correct answer is 550.

Key Points

  • Sugar substitutes are substances that substitutes sweeteners. They may also be called "artificial sweeteners". Ex. Saccharine, Sucralose, Aspartame, Alitame etc.
  • Natural sweeteners add to calorie intake and therefore many people prefer to use artificial sweeteners. Ex. Lactose (milk), fructose (honey) etc.

Saccharin : 

  • It is an artificial sweetener that is 300–400 times sweeter than sugar.
  • It's popular as a zero-calorie substitute used in various foods including bakery products, drinks, jams, chewing gum, and tinned fruit etc.

Important Points

The sweetness value of artificial sweeteners is listed below : 

Aspartame100 times sweeter than cane sugar
Saccharin550 times sweeter than cane sugar
Sucralose600 times sweeter than cane sugar
Alitame2000 times sweeter than cane sugar

Question 153

The Greek thinker _______ classified animals according to their habitat.

  1. AOption (a)

    Mendel

  2. BOption (b)

    Archimedes

  3. COption (c)

    Aristotle

  4. DOption (d)

    Newton

View answer & explanation

Correct answer

Answer: (c)C.

Aristotle

Why this answer is correct

Concept-

  • Aristotle classified animals according to their habitat
  • Aristotle is the first individual to introduce a concept of the classification of organisms.

Key Points Aristotle is the first known person to develop the concept of biological classification.He classified them on the basis of land,air and water living organisms.

Animals are classified based on their habitat-

  • Terrestrial animals- Terrestrial animals are creatures that live on land. They usually stand on four legs. The sensory organs of terrestrial animals are well developed.Ex-tiger,lion,dogs etc.
  • Aquatic animals- Aquatic animals are those that livein or near water. Gills are specific respiratory organs found in many aquatic species.Ex-fish
  • Aerial animals- Aerial animals are creatures that live the most of their time in air. Birds are included in this category.

Additional Information

  • Mendel gave Mendel's laws of inheritance include law of dominance, law of segregation and law of independent assortment.
  • Archimedes and Newton were physicist.

Question 154

Which one of the following is not a form of Calcium Carbonate?

  1. AOption (a)

    Marble

  2. BOption (b)

    Limestone

  3. COption (c)

    Chalk

  4. DOption (d)

    Blackstone

View answer & explanation

Correct answer

Answer: (d)D.

Blackstone

Why this answer is correct

Explanation:

Calcium carbonate:

  • Calcium carbonate is a chemical compound with the formula CaCO3.
  • It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which is a type of sedimentary rock consisting mainly of calcite) and is the main component of eggshells, snail shells, seashells, and pearls.
  • A limestone is a form of calcium carbonate.
  • Other Different forms of calcium carbonate are Chalk and Marble.

Properties of Calcium Carbonate:

  • Molar mass - 100.0869 g/mol.
  • Odour - odourless.
  • Appearance - Fine white powder; chalky taste.
  • pH value - 9

Hence, Blackstone is not a form of Calcium Carbonate.

Question 155

What is the boiling point of Ethanol?

  1. AOption (a)

    290 K

  2. BOption (b)

    209 K

  3. COption (c)

    351 K

  4. DOption (d)

    111 K

View answer & explanation

Correct answer

Answer: (c)C.

351 K

Why this answer is correct

Explanation:

Ethanol:

  • Ethanol is commonly known as Ethyl Alcohol.
  • Its chemical formula is C2H5OH.
  • Ethanol is a very good solvent. Many compounds that are insoluble in water are soluble in Ethyl Alcohol.
  • It is used in many medicines, such as tincture iodine, cough syrups, etc.
  • The melting point of Ethanol is – 114° C and the boiling point is 78.37°C or 351 K, which is very low with respect to water.

Ethanol can be used as follows:

  • Manufacture of organic compounds like acetaldehyde, acetic acid, and chloroform.
  • Manufacturing of house paints.
  • Pharmaceutical preparations like tincture of iodine, cough syrups, and tonics.
  • Used as a preservative for the biological specimens.
  • Alcoholic beverages.
  • Used as gasoline in vehicles.

Additional Information

Denatured alcohol is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.

  • The term denatured alcohol refers to alcohol products adulterated with toxic and/or bad tasting additives (e.g., methanol, benzene, pyridine, castor oil, gasoline, isopropyl alcohol, and acetone), making it unsuitable for human consumption.
  • The most common additive used is methanol (5–10%), giving rise to the term methylated spirits. Denatured alcohol is used as a lower-cost solvent or fuel for home-scale or industrial use.

Question 156

Complete the chemical reaction-

Metal carbonate/Metal hydrogencarbonate + Acid → _______

  1. AOption (a)

    Salt + Water

  2. BOption (b)

    Salt + Carbon dioxide + Water

  3. COption (c)

    Salt + Carbon dioxide

  4. DOption (d)

    Salt + Carbon mono-oxide + Water

View answer & explanation

Correct answer

Answer: (b)B.

Salt + Carbon dioxide + Water

Why this answer is correct

Explanation:

When an acid reacts with a metal carbonate or metal hydrogen carbonate, it gives the corresponding salt, carbon dioxide gas, and water.

NaHCO3 + HCl → NaCl + H2O + CO2

Important Points

  • Uses of sodium hydrogen carbonate (NaHCO3):
  • For making baking powder, which is a mixture of baking soda (sodium hydrogen carbonate) and a mild edible acid such as tartaric acid. When baking powder is heated or mixed in water, the following reaction takes place –
  • NaHCO3+ H+→ CO2+ H2O + Sodium salt of an acid.
  • Carbon dioxide produced during the reaction causes bread or cake to rise to make them soft and spongy.
  • Sodium hydrogen carbonate is also an ingredient in antacids.
  • Being alkaline, it neutralizes excess acid in the stomach and provides relief.
  • It is also used in soda-acid fire extinguishers.
  • Bleaching powder is used:
  • For bleaching cotton and linen in the textile industry, for bleaching the wood pulp in paper factories and for bleaching washed clothes in the laundry.
  • As an oxidizing agent in many chemical industries.
  • For disinfecting drinking water to make it free of germs.
  • Uses of washing soda:
  • Sodium carbonate (washing soda) is used in glass, soap and paper industries.
  • It is used in the manufacture of sodium compounds such as borax.
  • Sodium carbonate can be used as a cleaning agent for domestic purposes.
  • It is used for removing the permanent hardness of the water.

Question 157

<br>

Above given is the formula of :

  1. AOption (a)

    Lauryl Alcohol

  2. BOption (b)

    Glycerol

  3. COption (c)

    Dodecylbenzene

  4. DOption (d)

    Glyceryl ester

View answer & explanation

Correct answer

Answer: (b)B.

Glycerol

Why this answer is correct

The correct answer is option 2 that is Glycerol.

Concept:

  • A straightforward polyol chemical, glycerol is sometimes referred to as glycerin or glycerine. An alcohol that has several hydroxyl groups is referred to as a polyol.
  • Glycerol is a triol because its molecule contains three carbon atoms, each of which has an attached hydroxyl (OH) group. Glycerol is a flexible molecule with a wide range of interactions due to the three hydroxyl groups it possesses.
  • Glycerol is a very tiny molecule with a backbone-like structure made up of three carbon atoms arranged in a straight line, with hydroxyl groups extending from each carbon atom.

Explanation:

  • Glycerol, sometimes referred to as glycerin or glycerine, has the chemical formula C3H8O3.
  • The complete structural formula of this compound is HOCH2CH(OH)CH2OH. This proves that glycerol is a triol, a molecule with three alcohol functional groups, and that each of its three carbon atoms is connected to a hydroxyl (-OH) group.

Question 158

Addison's disease caused due to hyposecretion of _______.

  1. AOption (a)

    Insulin

  2. BOption (b)

    Thyroid hormone

  3. COption (c)

    Aldosterone

  4. DOption (d)

    ACTH

View answer & explanation

Correct answer

Answer: (c)C.

Aldosterone

Why this answer is correct

Concept -

  • When the functioning of one or more organs or systems of the body is adversely affected, characterized by various signs and symptoms, we say that we are not healthy, i.e., we have the disease.
  • The disease can be broadly grouped into infectious and non-infectious.
  • Hormones are non-nutrient chemicals.
  • A physical change occurs in the body by certain chemical substances are called hormones.
  • The hormone is secreted by the endocrine glands into the blood.

Explanation-

  • Hyposecretion of both cortisol and aldosterone leads to Addison's disease.
  • It is due to underactivity of the adrenal cortex which may be due to the destruction of cells by diseases like TB.
  • It is characterized by-
  • Excessive loss of Na+, Cl- and HCO3-
  • Increased K+ level in blood
  • Dark bronze colour pigmentation of the skin
  • Decreased resistance to infection
  • Low blood pressure

Therefore the correct option is 3.

Additional Information

Insulin

  • The pancreas is a composite gland that acts as both exocrine and endocrine glands.
  • The endocrine pancreas consists of ‘Islets of Langerhans’.
  • There are about 1 to 2 million Islets of Langerhans in a normal human pancreas representing only 1 to 2 percent of the pancreatic tissue.
  • The two main types of cells in the Islet of Langerhans are called α-cells and β-cells.
  • The α-cells secrete a hormone called glucagon, while the β-cells secrete insulin.

Thyroid hormone

  • This hormone increases metabolism & blood pressure.
  • Iodine is essential for the synthesis of the thyroxine hormone.
  • It can be obtained from fishes, green leafy vegetables, iodised salt.
  • It regulates tissue growth.
  • It along with hormones from the Pituitary gland regulates the water level balance in the human body.

ACTH

  • It is produced by the anterior pituitary gland.
  • It stimulates the adrenal gland to produce cortisol and other hormones.
  • ACTH also increase the concentration of cholesterol within the gland.

Question 159

Which acid is present in Tamarind?

  1. AOption (a)

    Citric acid

  2. BOption (b)

    Oxalic acid

  3. COption (c)

    Tartaric acid

  4. DOption (d)

    Acetic acid

View answer & explanation

Correct answer

Answer: (c)C.

Tartaric acid

Why this answer is correct

Concept :

  • Naturally occurring acids that occur naturally in foods.
  • Food acids are the important acids found in natural food products that give them a distinct flavor or a tinge.
  • The human body tends to react differently to different types of food acids.
  • There are different types of food acids like citric acid, malic acid, and tartaric acid that are naturally occurring food acids.

Hence we can conclude that Tartaric acid is present in Tamarind.

Additional Information

​Acid present in natural source with their pH:

Natural SourceAcidpH
VinegarAcetic acid2.5
AppleMalic acid3.30-4.00
TamarindTartaric acid1.8 to 3.7
MilkLactic acid6.5-6.8
Lemon juiceCitric acid2.00-2.60
TomatoOxalic acid4.30-4.90
GrapesTartaric acid3.00-3.75

Hint

  • Tomato contains more than 10 types of acids such as citric acid, malic acid, ascorbic acid, and oxalic acid etc.
  • Ant sting contain Methanoic acid.

Question 160

How does the colour of silver chloride change in sunlight?

  1. AOption (a)

    White to Grey

  2. BOption (b)

    Grey to White

  3. COption (c)

    White to Green

  4. DOption (d)

    Green to White

View answer & explanation

Correct answer

Answer: (a)A.

White to Grey

Why this answer is correct

Explanation:

Silver chloride (AgCl) is a chemical compound that is often used in photographic processes and as a reference in analytical chemistry. It is known for its photosensitivity, which means it undergoes a change in color when exposed to light, especially ultraviolet (UV) light from the sun. This color change is due to a chemical reaction that takes place when silver chloride absorbs photons of sufficient energy to initiate the reaction.

1. Initial State (White): In its natural state, silver chloride appears as a white crystalline solid.

This is because it reflects all visible light wavelengths and appears white to our eyes.

2. Exposure to Sunlight: When silver chloride is exposed to sunlight, it starts to undergo a photochemical reaction.

The ultraviolet (UV) component of sunlight contains photons with enough energy to break the bonds between the silver (Ag) and chlorine (Cl) atoms in the crystal lattice of silver chloride.

3. Formation of Silver and Chlorine Atoms: As the UV photons are absorbed, they cause the silver chloride to decompose into its constituent elements: silver (Ag) and chlorine (Cl).

  • This is a photochemical decomposition reaction:
  • 2AgCl (s)  →  2Ag (s) + Cl2 (g)
  • In this reaction, the silver chloride breaks down into silver atoms and chlorine molecules.
  • The silver atoms are responsible for the change in color.

4. Formation of Gray Silver: As the silver atoms are released, they start to aggregate and form small clusters of metallic silver within the crystal lattice.

These tiny silver particles are responsible for the gray color that develops in the silver chloride.

5. Color Change (White to Gray): As more and more silver atoms aggregate and form small silver clusters, the overall appearance of the silver chloride changes from white to gray.

The extent of the color change depends on the duration and intensity of sunlight exposure.

6. Reversibility: It's important to note that the color change in silver chloride is reversible.

When removed from sunlight and stored in a dark place for an extended period, the gray color will gradually fade, and the silver chloride will return to its original white color.

This reversibility is a key property that makes silver chloride useful in photographic processes.

So, in summary, the color change of silver chloride in sunlight is due to the photochemical decomposition of silver chloride into silver and chlorine, with the formation of small silver clusters that impart a gray color to the material.

Discipline 4 (20 questions)

Question 161

A gene is a relatively short length of DNA that codes for a _______.

  1. AOption (a)

    Fats

  2. BOption (b)

    Protein

  3. COption (c)

    Lipid

  4. DOption (d)

    Carbohydrates

View answer & explanation

Correct answer

Answer: (b)B.

Protein

Why this answer is correct

The correct answer is Protein.

Explanation:

  • DNA (deoxyribonucleic acid) is a double-stranded structure.
  • DNA acts as the genetic material in almost all living organisms.
  • Chromosomes is made up of DNA and protein.
  • Chromatin fibers look like beads on the string, where beads are repeated units of protein.
  • Protein associated with DNA are of two types basic proteins (histone and protamine) and acidic non-histone chromosomal proteins.
  • Genes (functional segments of DNA) are known to be located on chromosomes.
  • Most genes contain the information needed to make functional molecules known as proteins.
  • Genes are small segments of DNA in the genome that code for protein.

Thus, A gene is a relatively short length of DNA that codes for a protein.

Question 162

All the involuntary actions including blood pressure salivation and vomiting are controlled by _______ in the Hind brain.

  1. AOption (a)

    Thalamus

  2. BOption (b)

    Cerebrum

  3. COption (c)

    Medulla

  4. DOption (d)

    Cerebellum

View answer & explanation

Correct answer

Answer: (c)C.

Medulla

Why this answer is correct

The correct answer is Medulla.

Explanation:

  • Medulla is the part of the brain (Hindbrain).
  • Brain is the central information processing organ of our body and acts as the 'command and control sysem' of all body activities.
  • It is the lowest part of the brain as well as the lowest portion of the brainstem.
  • Medulla (oblongata) of the brain is connected to the spinal cord.
  • The medulla contains centres, which control respiratory rhythm, cardiovascular reflexes, gastric secretions, and the postural gestures of the body.
  • Therefore, It controls all the involuntary actions including blood pressure, salivation and vomiting.
  • It also plays an important role in transmitting messages between spinal cord and brain.

Additional Information

  • The heart is located between the lungs in the middle of the body.
  • The heart comprises chambers, valves, vessels, wall, and conduction system.
  • The lungs are a pair of spongy air-filled organs located on either side of the chest.
  • It is used for respiration
  • The eye consists of the sclera, cornea, pupil, lens, retina, vitreous humor, and anterior & posterior chambers.

Question 163

Which part of cell nucleus is the information source for making protein?

  1. AOption (a)

    Nucleolus 

  2. BOption (b)

    Mitochondria

  3. COption (c)

    DNA

  4. DOption (d)

    Ribosomes

View answer & explanation

Correct answer

Answer: (c)C.

DNA

Why this answer is correct

Concept-

  • A nucleus is a membrane-bound organelle that contains the cell's chromosomes.
  • The nucleus controls and regulates the activities of the cell.
  • It also carries the genes, structures that contain the hereditary information.

Key Points

  • The DNA in the cell nucleus is the information source for making proteins.
  • It is also the site of synthesis for ribosomes, the machine that assembles proteins.
  • First DNA replicates itself, then DNA is transcribed into a messenger RNA (mRNA - ribonucleic acid) molecule during transcription(formation of mRNA from DNA).
  • mRNA then gets translated(formation of protein from mRNA) to produce a protein.

Additional Information  Nucleolus-

  • Nucleolus is the distinct structure present in the nucleus of eukaryotic cells.
  • Nucleolus is composed of RNA and proteins
  • It participates in assembling the ribosomes, alteration of transfer RNA.

Mitochondria-

  • Mitochondria is cell organelles, or part of a eukaryote cell. They are in the cytoplasm, not the nucleus.
  • They make most of the cell's supply of adenosine triphosphate (ATP), a molecule that cells use as a source of energy.

Ribosomes-

  • Ribosome is a complex molecule made of ribosomal RNA molecules and proteins.
  • It form a factory for protein synthesis in cells.

Question 164

Which of the following effects is not covered in the term water pollution?

  1. The addition of undesirable substances to bodies.
  2. A change in temperature of water bodies.

Choose the correct code.

  1. AOption (a)

    Only 1

  2. BOption (b)

    Both 1 and 2

  3. COption (c)

    Neither 1 nor 2

  4. DOption (d)

    Only 2

View answer & explanation

Correct answer

Answer: (c)C.

Neither 1 nor 2

Why this answer is correct

Concept-

  • Water pollution is caused by the addition of organic and inorganic chemicals as well as biological materials which change the physical and chemical properties of water.
  • This harmful process is called water pollution.
  • Water pollution is caused by many sources such as sewage matter, industrial wastage, agricultural wastage, domestic wastage, hot water of thermal plants and nuclear reactors, etc.
  • A mere 0.1 percent of impurities make domestic sewage unfit for human use.

Explanation-

The addition of undesirable substances to bodies.

  • These substances could be the fertilizers and pesticides used in farming or they could be poisonous substances, like mercury salts which are used by paper industries.
  • These could also be disease-causing organisms, like the bacteria which cause cholera.

A change in temperature of water bodies.

  • Aquatic organisms are used to a certain range of temperature in the water-body where they live, and a sudden marked change in this temperature would be dangerous for them or affect their breeding.
  • The eggs and larvae of various animals are particularly susceptible to temperature changes.

Therefore Neither 1 nor 2 is not covered in the term water pollution.

Additional InformationThe removal of desirable substances from water bodies.

  • Dissolved oxygen is used by the animals and plants that live in water. Any change that reduces the amount of this dissolved oxygen would adversely affect these aquatic organisms.
  • Other nutrients could also be depleted from the water bodies.

Question 165

Which of the following is a Kharif crop?

  1. AOption (a)

    Masoor

  2. BOption (b)

    Potatoes

  3. COption (c)

    Sunflower

  4. DOption (d)

    Barley

View answer & explanation

Correct answer

Answer: (c)C.

Sunflower

Why this answer is correct

India has three distinct crop seasons in the northern and interior parts of the country, namely Kharif, Rabi, and Zaid.

Important Points

Lets' look at the cropping season of India:

  • The Kharif season (June-September) largely coincides with Southwest Monsoon under which the cultivation of tropical crops are possible.
  • Major Crops- Rice, Cotton, Jute, Jowar, Bajra and Tur.
  • Sunflower is cultivated as both kharif and rabi seasons
  • The Rabi season (October-March) has low-temperature conditions which help in the cultivation of temperate and subtropical crops.
  • Major Crops- Wheat, Masoor, Barley, Gram, potato and Mustard.
  • The Zaid season (April-June) is a short duration summer cropping season beginning after harvesting Rabi crops.
  • Major Crops- Watermelons, Cucumbers, Vegetables, and Fodder Crops.

From the above, we can conclude that Sunflower is a Kharif crop.

Question 166

Nitrogen-fixing bacteria are found in-

  1. AOption (a)

    Legumes

  2. BOption (b)

    All species of dicot plants

  3. COption (c)

    All species of monocot plants

  4. DOption (d)

    Rice

View answer & explanation

Correct answer

Answer: (a)A.

Legumes

Why this answer is correct

Concept-

  • Microorganisms that are capable of transforming atmospheric nitrogen into fixed nitrogen(compounds usable by plants such as ammonia) are called nitrogen-fixing bacteria.
  • The process of transforming atmospheric nitrogen into fixed nitrogen is called nitrogen fixation.
  • They are commonly found in soil or in aquatic environments.

Key Points

  • The nitrogen-fixing bacteria are found in the roots of legumes in special structures called root nodules.
  • Leguminous plants belong to the family Fabaceae.
  • These plants form a symbiotic association with the soil bacteria called the Rhizobium, which lives in their roots, forming root nodules and fixing atmospheric nitrogen into the nitrates and nitrites for the plants and the plants provide nutrition to the bacteria.

Question 167

Which of the following vitamins' deficiency causes Beriberi?

  1. AOption (a)

    Vitamin A

  2. BOption (b)

    Vitamin D

  3. COption (c)

    Vitamin C

  4. DOption (d)

    Vitamin B1

View answer & explanation

Correct answer

Answer: (d)D.

Vitamin B1

Why this answer is correct

The correct answer is Vitamin B1. 

Explanation:

  • Vitamins are organic substances that we need in sufficient quantities to maintain good health.
  • Our body, however, cannot synthesise them. Therefore, we need to consume their natural sources such as fruits and vegetables. Vitamins are divided into two groups– water soluble vitamins (Vitamins of B group and Vitamin C) and fat-soluble vitamins (Vitamins A, D, E, and K).
  • The sources of Vitamin B1 are seafood, milk, meat, peas, cereals, green vegetables, etc.
  • Vitamin B1 is essential for growth and development, releasing energy from carbohydrates.
  • Deficiency of vitamin B1 causes beri beri.
  • Each vitamin has a specific function and its deficiency leads to a particular deficiency disease.

Additional Information

Name of VitaminSourcesNeedDeficiency diseases
Vitamin AMilk, butter, egg, carrots, cod liver oil, tomatoes, pumpkin, green leafy vegetablesNormal growth and to keep eyes and skin healthyNight blindness, Irregular growth of teeth
Vitamin DCheese, butter, milk, green vegetables, fish liver oil, sunlightFormation of strong bones and teethRickets
Vitamin CIndian gooseberry (amla), lemons, lime, pineapple, oranges, watermelon, green peppers, tomatoes, cabbage, turnip, carrots, green mint, guavaMaintenance of ligaments, tendons, other supportive tissues and blood vesselsScurvy (gums swell and bleed)

Question 168

Light enters the eye through a thin membrane called _______.

  1. AOption (a)

    Retina

  2. BOption (b)

    Cornea

  3. COption (c)

    Vitreous humour

  4. DOption (d)

    Aqueous humour

View answer & explanation

Correct answer

Answer: (b)B.

Cornea

Why this answer is correct

Explanation: 

​The human eye consists of a thin membrane in the front portion through which light enters. It is called the cornea.

  • The pupil is a hole through which light enters into our eye.
  • It controls the amount of light entering the eye.
  • Iris is a muscle in our eye that controls the size of the pupil. It dilates and contracts because of which size of the pupil varies.
  • So we can say Iris controls the size of the pupil.
  • Cornea: The frontmost and transparent covering of the eye is called Cornea.
  • Light enters the human eye through the cornea.
  • Aqueous Humor: The clear watery and transparent fluid that circulates in the front part of the eye is called Aqueous Humor.
  • Aqueous humor is a fluid or transparent window that keeps constant pressure within the eye and further nourishes the cornea and lens.

​

Important Points

  • Different parts of the eyes and their functions are shown in the table:
Name of the PartCharacteristicsFunction
CorneaThe transparent spherical membrane covering the front part of the eyeLight enters the eye through this membrane; Most of the refraction happens here
Eye Lenstransparent, biconvex structure in the eyeprovides finer adjustment required to focus objects on the retina
IrisThe dark muscular diaphragm between the cornea and the lenscontrols the size of the pupil
PupilAn opening between the iris through which light enters the eyeregulates the amount of light entering the eye
Ciliary MusclesAttached to the eye lens
hold the lens in position and modify the curvature of the lens.
Retinathe light-sensitive surface of an eye on which the image is formedgenerate signals which are transmitted to the brain through optical nerves
Optic NerveAttached to retinatransmits visual information from the retina to the brain

Question 169

Peripheral nervous system consists of-

  1. AOption (a)

    Spine, Spinal nerve

  2. BOption (b)

    Brain, nerve cord

  3. COption (c)

    Cranial nerve, Spinal nerve

  4. DOption (d)

    Brain, cranial nerve

View answer & explanation

Correct answer

Answer: (c)C.

Cranial nerve, Spinal nerve

Why this answer is correct

Concept-

  • The Human neural system is divided into two parts-
  • Central neural system - consists of the brain and the spinal cord and is the site of information processing and control.
  • The peripheral neural system - the nerve arising from the CNS, constitutes the PNS.
  • The nerve fibres of the PNS are of two types-
  • Afferent fibres (Sensory)- Conducts impulses from receptors to the CNS.
  • Efferent fibres (Motor)- Conducts impulses from CNS to effectors (muscles and glands).

Explanation-

  • The PNS is divided into two divisions-
  • Somatic neural system (SNS)- controls and coordinate those organs which are under voluntary control.
  • Autonomic neural system (ANS)- controls and coordinate those organs which are under involuntary control.
  • All the nerves arising from the brain and spinal cord are included in PNS.
  • Nerves that come from the brain are called cranial nerves.
  • And nerves that come from the spinal cord are called spinal nerves.
  • 12 pairs of cranial nerves are found in mammals.
  • 31 pairs of spinal nerves are found in humans.

Therefore Peripheral nervous system consists of the Cranial nerve, Spinal nerve.

Additional Information

  • Central Nervous System-
  • It is a part of the nervous system which keeps control of the whole body and the nervous system itself.
  • It is made up of two parts - The brain and Spinal Cord.

Question 170

Which part of the eye is a dark muscular diaphragm that controls the size of the pupil?

  1. AOption (a)

    Iris

  2. BOption (b)

    Pupil

  3. COption (c)

    Cornea

  4. DOption (d)

    Vitreous humour

View answer & explanation

Correct answer

Answer: (a)A.

Iris

Why this answer is correct

Explanation:

Iris: A dark muscular tissue and ring-like structure behind the cornea are known as the iris.

  • The colour of the iris actually indicates the colour of the eye.
  • The iris also helps regulate or adjust exposure by adjusting the iris.
  • The iris is divided into two major regions:
  • The pupillary zone is the inner region whose edge forms the boundary of the pupil.
  • The ciliary zone is the rest of the iris that extends to its origin at the ciliary body.
  • Control pupil size is the function of an important part of the human eye, the iris.
  • It controls how much light enters the eye by changing the size of the pupil.
  • Eye colour is defined by the iris.
  • In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm.

Additional Information

Retina:

  • It contains highly specialized nerve cells.
  • These convert the light which is focused there into electrical signals.
  • These are then passed through the optic nerves to the parts of the brain which process vision and build up the picture that we see.
  • It is a light-sensitive layer that consists of numerous nerve cells.
  • It converts images formed by the lens into electrical impulses.

Pupil:

  • A small opening in the iris is known as a pupil.
  • Its size is controlled with the help of the iris.
  • It controls the amount of light that enters the eye.
  • Lens:
  • Behind the pupil, there is a transparent structure called a lens.
  • By the action of ciliary muscles, it changes its shape to focus light on the retina.
  • It becomes thinner to focus on distant objects and becomes thicker to focus on nearby objects.

Cornea:

  • The front transparent part of the sclera is called the cornea.
  • Light enters the eye through the cornea.

Question 171

Bombay duck is a type of-

  1. AOption (a)

    Weed

  2. BOption (b)

    Cattle

  3. COption (c)

    Fish

  4. DOption (d)

    Bird

View answer & explanation

Correct answer

Answer: (c)C.

Fish

Why this answer is correct

Concept-

Fishes are the aquatic organisms belonging to superclass Pisces of phylum Chordata.

Key Points

  • Bombay duck, (Harpadon nehereus), fish of the family Synodontidae, found in estuaries of northern India.
  • It is widely used for consumption.
  • Bombay duck grows to a length of about 41 cm (16 inches) and is a dull, translucent gray or brown in color with small, dark speckles.
  • It has a largemouth, a forked tail, and large pectoral and pelvic fins.

Additional InformationWeed are unwanted plants.

Question 172

Which of the following is not a vestigial organ of human?

  1. AOption (a)

    Heart

  2. BOption (b)

    Wisdom teeth

  3. COption (c)

    Nictitating membrane of eye

  4. DOption (d)

    Vermiform appendix

View answer & explanation

Correct answer

Answer: (a)A.

Heart

Why this answer is correct

Concept-

Vestigial organs are the organs that once were useful in an animal's body millions of years ago, but now they are useless or very close to useless.

Key Points Human heart-

  • The human heart is not vestigial as at present times it has its own functions in the human body.
  • The human heart is an organ that pumps blood throughout the body.
  • Heart pumps the blood through the vessels of the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes.
  • The tissues of the body need a constant supply of nutrition in order to be active which is performed by blood.

Additional Information Wisdom teeth

  • Wisdom teeth are no longer totally necessary. Today, humans cook food to soften it, and we can cut and crush it with utensils.So at this time they are vestigial.
  • Early humans needed to chew coarse, hearty foods, they required a broader jaw.
  • Wisdom teeth grew in to give them more chewing power for this purpose.

Nictitating membrane of eye

  • In humans, the nictitating membrane is the pink lump in the inner corner of the eyes which is known as the caruncula lacrimalis.
  • In this structure, the remaining of the nictitating membrane are permanently folded into that corner and no longer functional.So it is vestigial.

Vermiform appendix

  • The human appendix may be considered as a vestigial organ as it has been proved that the removal of the organ after infancy does not create any harm.
  • Its function is to digest cellulose.

Question 173

Which of the following is NOT a way how insect pests attach the plants?

  1. AOption (a)

    They cut the root, stem and leaf.

  2. BOption (b)

    They bore into stems and fruits.

  3. COption (c)

    They suck the cell-sap from various parts of plants.

  4. DOption (d)

    They block the stomata on the leaves, thus stopping photosynthesis.

View answer & explanation

Correct answer

Answer: (d)D.

They block the stomata on the leaves, thus stopping photosynthesis.

Why this answer is correct

The correct option is 4(They block the stomata on the leaves, thus stopping photosynthesis).

Key Points

Generally, insect pests attack the plants in three ways-

  • they cut the root, stem, and leaf,
  • they suck the cell sap from various parts of the plant, and
  • they bore into stems and fruits.

They thus affect the health of the crop and reduce yields.

Additional Information

  • Fungal, bacterial, viral, and nematode pathogens attack the cultivated crops.
  • Crop losses up to 20-30 percent.
  • Insects and pest infections are two major causes of the destruction of crop plants and crops.
  • Insects can be controlled by various methods-
  • One of the most commonly used methods is the use of insecticides.
  • These chemicals are sprayed on crop plants or used for treating seeds and soil.

Question 174

Which of the following crops is a major sources of carbohydrates for energy requirement?

  1. AOption (a)

    Linseed

  2. BOption (b)

    Sorghum

  3. COption (c)

    Fruits

  4. DOption (d)

    Black gram

View answer & explanation

Correct answer

Answer: (b)B.

Sorghum

Why this answer is correct

The correct answer is Sorghum.

Explanation:

  • Carbohydrates, vitamins, fats, proteins and minerals are components of food.
  • Carbohydrates mainly provide energy to our body.
  • Carbohydrate-containing foods are also referred as 'energy-giving foods.'
  • The major carbohydrates found in our food are in the form of starch and sugars.
  • These can be found in fruits, vegetables, dairy products, and grains.
  • Rice is a carbohydrate-rich source of food
  • These of carbon, hydrogen and oxygen.
  • Sorghum is the major source of carbohydrates for energy requirements.
  • Sorghum is a great source of energy, primarily in the form of complex carbohydrates.

Additional Information

  • Black gram (urad) provide us with protein
  • linseed (oil seed) provide us with necessary fats.
  • Fruits provide a range of vitamins and minerals in addition to small amounts of proteins, carbohydrates, and fats.

Question 175

The term gene was coined by-

  1. AOption (a)

    Mendel

  2. BOption (b)

    Johannsen

  3. COption (c)

    Lamarck

  4. DOption (d)

    Newton

View answer & explanation

Correct answer

Answer: (b)B.

Johannsen

Why this answer is correct

The correct answer is Johannsen.

Explanation:

  • Danish botanist Wilhelm Johannsen (1857–1927) coined the term  'gene' in 1909.
  • Wilhelm Johannsen described the Mendelian units of heredity.
  • Gene is the unit of inheritance. They contain the information that is required to express a particular trait in an organism.

Additional Information

Gregor Mendel

  • Gregor Mendel (1822-1884) is known as 'Father of Genetics'.
  • Mendel performed his experiments with garden pea plant (Pisum Sativum).

Jean-Baptiste Lamarck 

  • Jean-Baptiste Lamarck (1744 –1829) gave the theory of inheritance of acquired characteristics.
  • According to Lamarck, evolution of life forms occurred due to use and disuse of organs.

Isaac Newton

  • Newton (1642 – 1726) formulated the laws of motion.
  • Newton concluded that not only does the earth attract an apple and the moon but all objects in the universe attract each other.

Question 176

Which of the following are sources of sulphur oxides?

  1. Combustion of coal
  2. Combustion of petroleum
  3. Volcanoes

Select the correct answer using the code given below.

  1. AOption (a)

    1, 2 and 3

  2. BOption (b)

    Only 2 and 3

  3. COption (c)

    Only 1 and 3

  4. DOption (d)

    Only 1 and 2

View answer & explanation

Correct answer

Answer: (a)A.

1, 2 and 3

Why this answer is correct

Explanation:

  • Sulphur Oxide is a pollutant to the environment like sulfur dioxide SO2  and sulfur trioxide SO3, they are released in the process of complete and incomplete combustion. Sulfur oxides are the main cause of Acid Rain as well.
  • The burning of anything in the presence of air ( Oxygen) is called combustion.
  • Combustion of Coal and Petroleum releases smoke, carbon dioxide, carbon monoxide, sulfur oxides, Nitrogen oxides, Particulate matter, etc.
  • Therefore the combustion process of coal and petroleum are the main sources of Sulphur oxides.
  • In Volcanic eruptions, the magma which is released contains dissolved gases like carbon dioxide, sulfur dioxide, Halides of Hydrogen, and  Hydrogen Sulphide.
  • Thus, a volcanic eruption is also a major source of sulfur oxides.

Additional Information

  • Sulfur dioxide causes harm to the respiratory systems.
  • It can cause chronic diseases such as Asthma and Bronchitis etc.

Question 177

In what ways can carbon dioxide be used?

  1. In food-preservation
  2. Refrigerant

Select the correct code.

  1. AOption (a)

    Neither 1 nor 2

  2. BOption (b)

    Only 1

  3. COption (c)

    Both 1 and 2

  4. DOption (d)

    Only 2

View answer & explanation

Correct answer

Answer: (c)C.

Both 1 and 2

Why this answer is correct

Concept-

  • Carbon dioxide is a colorless and odorless gas.
  • Carbon dioxide can be obtained as a solid in the form of dry ice by allowing the liquified CO2 to expand rapidly.
  • Gaseous CO2 is extensively used to carbonated soft drinks.
  • It is used as a fire extinguisher.

Explanation-

  • Dry ice(carbon dioxide) is used as a refrigerant for ice cream and frozen food.
  • Carbon dioxide helps preserve packaged food by decreasing the amount of oxygen inside the package.
  • Carbon dioxide also prevents bacteria growth and lowers the pH of preserved food.
  • Carbon monoxide is used in meat packaging.
  • Carbon Dioxide is commonly used to prevent the growth of mold and bacteria and is used to maintain longer shelf life.

Therefore carbon dioxide is used In food preservation and Refrigerant.

Question 178

Which of the following plant-hormones inhibit growth?

  1. AOption (a)

    Abscisic acid

  2. BOption (b)

    Gibberellins

  3. COption (c)

    Auxins

  4. DOption (d)

    Cytokinins

View answer & explanation

Correct answer

Answer: (a)A.

Abscisic acid

Why this answer is correct

The correct answer is Abscisic acid.

Explanation:

  • Abscisic acid is a slightly acidic growth hormone that functions as a growth inhibitor by counteracting with other growth hormones, i.e., auxins, gibberellins and cytokinins.
  • Thus, like other Plant growth regulators, Abscisin acid also has a wide range of effects on the growth and development of plants.
  • The small, simple molecules secreted in minute quantities, that influence various physiological functions in plants are called plant growth regulators.
  • Abscisic acid has a primary role in regulating the abscission and dormancy of buds and seeds.
  • Abscisic acts as a general plant growth inhibitor and also inhibits the metabolism of plants.
  • It also has a role in the inhibition of seed germination.

Thus, Abscisic acid plant-hormone inhibit growth.

Important PointsEthylene Hormone: This hormone is a critical regulator of plant growth and development. It is best known for its effect on fruit ripening and organ abscission.

Question 179

The light sensitive screen of eye is known as _______.

  1. AOption (a)

    Optic nerve

  2. BOption (b)

    Retina

  3. COption (c)

    Aqueous honour

  4. DOption (d)

    Pupil

View answer & explanation

Correct answer

Answer: (b)B.

Retina

Why this answer is correct

Explanation: 

  • The pupil is light sensitive and it is a hole through which light enters into our eye.
  • It controls the amount of light entering the eye.
  • Iris is a muscle in our eye that controls the size of the pupil. It dilates and contracts because which size of the pupil varies.
  • So we can say Iris controls the size of the pupil.
  • Cornea: The frontmost and transparent covering of the eye is called Cornea.
  • Light enters the human eye through the cornea.
  • Aqueous Humor: The clear watery and transparent fluid that circulates in the front part of the eye is called Aqueous Humor.
  • Aqueous humor is a fluid or transparent window that keeps constant pressure within the eye and further nourishes the cornea and lens.
  • Retina: Retina is the light-sensitive surface of an eye on which the image is formed.
  • It generate signals which are transmitted to the brain through optical nerves

​

Important Points

  • Different parts of the eyes and their functions are shown in the table:
Name of the PartCharacteristicsFunction
CorneaThe transparent spherical membrane covering the front part of the eyeLight enters the eye through this membrane; Most of the refraction happens here
Eye Lenstransparent, biconvex structure in the eyeprovides finer adjustment required to focus objects on the retina
IrisThe dark muscular diaphragm between the cornea and the lenscontrols the size of the pupil
PupilAn opening between the iris through which light enters the eyeregulates the amount of light entering the eye
Ciliary MusclesAttached to the eye lens
hold the lens in position and modify the curvature of the lens.
Retinathe light-sensitive surface of an eye on which the image is formedgenerate signals which are transmitted to the brain through optical nerves
Optic NerveAttached to retinatransmits visual information from the retina to the brain

Question 180

Amoeba reproduces by _______.

  1. AOption (a)

    Regeneration

  2. BOption (b)

    Fragmentation

  3. COption (c)

    Binary fission

  4. DOption (d)

    Vegetative propagation

View answer & explanation

Correct answer

Answer: (c)C.

Binary fission

Why this answer is correct

The correct answer is Binary fission.

Explanation:

  • Amoeba is a single-celled microscopic organism found in pond water.
  • In its cytoplasm, amoeba has a cell membrane, a rounded, dense nucleus, and numerous small bubble-like vacuoles.
  • Amoeba constantly changes its shape and position.
  • Amoeba reproduces asexually by the process of Binary fission.
  • Asexual reproduction is common among single-celled organisms.
  • In binary fission, the parent body divides into two equal daughter cells and each rapidly grow into an adult.
  • In this reproduction, two similar organisms are produced from the single parent.
  • It can be simple or irregular, longitudinal, oblique or transverse, depending on the plane of division.

​

Discipline 5 (10 questions)

Question 181

Which of the following statements is incorrect?

  1. AOption (a)

    CNG through eco-friendly is expensive as compared to petrol or diesel.

  2. BOption (b)

    CNG can't be adulterated by petrol or diesel.

  3. COption (c)

    It burns without leaving any unburnt remnant behind.

  4. DOption (d)

    CNG burns most efficiently.

View answer & explanation

Correct answer

Answer: (a)A.

CNG through eco-friendly is expensive as compared to petrol or diesel.

Why this answer is correct

Concept:

  • Compressed natural gas, CNG, is natural gas under pressure which remains clear, odorless, and non-corrosive.
  • It is considered better over diesel/petrol because of the following reasons-
  • It burns most efficiently without leaving any unburnt remnant behind.
  • It is cheaper than petrol or diesel and less polluting than petrol.
  • It cannot be adulterated easily like petrol or diesel.
  • Caloric values of CNG and petrol are 50,000 kJ/kg and 45000 kJ/kg respectively. So, CNG is more effective.
  • The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its calorific value.
  • The calorific value of a fuel is expressed in a unit called kilojoule per kilogram (kJ/kg).
  • CNG is used for power generation.
  • It is now being used as a fuel for transport vehicles because it is less polluting.
  • Compressed natural gas disperse easily when released.
  • It produces more heat than petrol as this disperses more easily when released due to high calorific value.
  • CNG tanks require more space and are heavy.

Hence we can conclude that CNG through eco-friendly is expensive as compared to petrol or diesel is not correct.

Question 182

Which of the following is considered to be the purest form of water?

  1. AOption (a)

    Rain water

  2. BOption (b)

    Spring water

  3. COption (c)

    River water

  4. DOption (d)

    Well water

View answer & explanation

Correct answer

Answer: (a)A.

Rain water

Why this answer is correct

Explanation:

Rainwater is considered the purest form of water.

  • Impurities and salts present in water on earth are left behind during vaporisation by the sun.
  • However, the rain water we receive on earth is not necessarily pure, as it brings down impurities and particles present in the atmosphere along with it.
  • Rainwater is considered to be the purest form of natural water as it is directly coming from the condensation of water droplets.
  • In the presence of the sun, the water evaporates from the seas, oceans, rivers (from all the natural open resources of water) leaving behind all the impurities and form the cloud.
  • A new scientific study concluded that the world's purest water can be found in freshwaters of Puerto Williams in southern Chile.
  • The healthiest type of water is technically hydrogen water because of the potential health benefits of the antioxidants it contains.

​Spring water, river water, well water contains impurities like mud, sand, gravel, salts etc.

Additional Information Water Cycle:

  • ​Water is a cyclic resource. It can be used and re-used.

  • Water also undergoes a cycle from the ocean to land and land to the ocean.

  • The hydrological cycle describes the movement of water on, in, and above the earth.

  • The water cycle has been working for billions of years and all the life on earth depends on it.

  • Next to air, water is the most important element required for the existence of life on earth.

  • The hydrological cycle is the circulation of water within the earth’s hydrosphere in different forms i.e. the liquid, solid, and gaseous phases.

  • It also refers to the continuous exchange of water between the oceans, atmosphere, land surface and subsurface, and the organisms.

  • Water can neither be added nor subtracted from the earth. Its total volume remains constant.

Its abundance only seems to vary because it is in constant motion, cycling through the oceans, the air, the land and back again, through the processes of evaporation, precipitation and run-off. This as you already know is referred to as the ‘water cycle’.

Question 183

Which of the following statements is incorrect?

  1. AOption (a)

    Smog stays in the upper layers of atmosphere.

  2. BOption (b)

    Smog destroys crops and reduce crop-yields.

  3. COption (c)

    Exposure to smog causes respiratory problems.

  4. DOption (d)

    Smog formation is accompanied by Thermal inversion.

View answer & explanation

Correct answer

Answer: (a)A.

Smog stays in the upper layers of atmosphere.

Why this answer is correct

Explanation:

  • Smog is a mixture of Smoke and Fog. Smog is considered to be an air pollutant.
  • Smog is resulted due to the burning and combustion of coal and petroleum products.
  • The Petrochemical smog is formed due to the reaction of various  Nitrogen oxides with Ultra-violet rays from the sun.
  • In Summers, the formation of petrochemical smog is more as compared with winters. In the Winter season, Due to high atmospheric pressure and temperature inversions, winter smog takes place.
  • The presence of smog affects climate and temperature.
  • Being an air pollutant Smog causes Air Pollution which is the main cause of respiratory disorders in living organisms.
  • It is also harmful to plants as it blocks all the stomatal pores present in the leaves which disturbs the phenomenon of photosynthesis. Due to this the Crop production and yield are also affected on a great scale.

Smog is not only present in the Ozone as Ozone Smog but due to the combination of Smoke and fog, It is found to be suspended at the ground levels too. 

'Smog stays in the upper layers of atmosphere.' This is the only incorrect statement.

Question 184

Carrot grass is a type of-

  1. AOption (a)

    Cockleburs

  2. BOption (b)

    Parthenium

  3. COption (c)

    Cyprus rotundus

  4. DOption (d)

    Alligator weed

View answer & explanation

Correct answer

Answer: (b)B.

Parthenium

Why this answer is correct

Carrot grass is a type of Parthenium.

Key Points

  • Parthenium is a species of plant that belongs to the Asteraceae family.
  • It is commonly called carrot grass.
  • It is native to America.
  • Carrot grass is an exotic weed, which grows rapidly and affects the native species.
  • Environmental damage caused and the threat posed to our native species by invasive weed species like carrot grass (Parthenium).
  • It causes milk disease in livestock.
  • It causes allergies in humans which include respiratory problems.

Additional InformationAlligator weed

  • Alternanthera philoxeroides, commonly called alligator weed.
  • It is a native species to the temperate regions of South America.

Cockleburs

  • Cockleburs belong to the sunflower family (Asteraceae).
  • It is native to the Americas and eastern Asia and some parts of South Asia.

Cyperus rotundus

  • Cyperus rotundus commonly called coco-grass.

Question 185

Buffer stocks are those stocks of grains that are obtained by the government through the medium of _______,

  1. AOption (a)

    FICCI

  2. BOption (b)

    ISFER

  3. COption (c)

    ICAR

  4. DOption (d)

    FCI

View answer & explanation

Correct answer

Answer: (d)D.

FCI

Why this answer is correct

The correct answer is FCI.

Concept:

  • Food is as necessary for survival as air is for breathing.
  • But food security involves more than just eating two square meals a day.
  • The dimensions of food security are as follows.
  • Food availability refers to domestic food production, food imports, and previous year stock stored in government granaries.
  • Accessibility implies that food is within everyone's reach.
  • Affordability implies that a person has enough money to buy enough safe and nutritious food to meet his or her dietary needs.

Key Points

  • Buffer Stock is the government's stock of foodgrains, specifically wheat and rice, obtained through the Food Corporation of India (FCI).
  • The FCI buys wheat and rice from farmers in states where there is a surplus.
  • Farmers are paid a predetermined price for their crops. This is known as the Minimum Support Price (MSP).
  • Every year, before the sowing season, the government declares the MSP in order to provide incentives to farmers in order to increase crop production. Foodgrains purchased are stored in granaries.
  • Buffer Stock is done to distribute foodgrains in deficient areas and among the poorer strata of society at a lower-than-market price, also known as the Issue Price.
  • This also aids in resolving the issue of food scarcity amid poor weather conditions or disasters.

Question 186

To remove permanent hardness of water, we can add calculated amounts of-

  1. AOption (a)

    Calcium chloride

  2. BOption (b)

    Washing soda

  3. COption (c)

    Aluminium sulphate

  4. DOption (d)

    Hydrochloric acid

View answer & explanation

Correct answer

Answer: (b)B.

Washing soda

Why this answer is correct

Explanation:

Hardness of water: Hardness in water is that characteristic which prevents the formation of sufficient leather or foam, when such hard waters are mixed with soap. It is usually caused by the presence of calcium and magnesium salts present in water, which form scum by reaction with soap.

  • Water softening: The process of removal of hardness from water is known as Water softening.

Removal of hardness;

  1. Temporary hardness: The temporary or carbonate hardness, which is caused by carbonates and bicarbonates of Ca and Mg or bivalent cations.

The methods of removing temporary hardness:

  1. Boiling
  2. Addition of lime.
  3. Permanent hardness: The permanent or non-carbonate hardness, which is caused by the sulphates, chlorides and nitrates of Ca and Mg are removed by special methods.

The methods of removing permanent hardness

  • Lime soda process
  • Base exchange process
  • Demineralization​

Permanent Hardness: It is due to the presence of soluble salts of magnesium and calcium in the form of chlorides and sulphates in water.

  • Permanent hardness is not removed by boiling.
  • Ion-exchange method:
  • ​This method is also called the zeolite/permutit process.
  • In this method, the permanent hardness of water is removed by using resins.
  • Ca++/Mg++ ions are exchanged with Cl–, SO4-2 ions are exchanged with anion exchange resin (RNH2OH). Demineralized water is formed in this process.
  • Hydrated sodium aluminium silicate is zeolite/permutit.
  • For the sake of simplicity, sodium aluminium silicate (NaAlSiO4) can be written as NaZ.
  • When this is added to hard water, exchange reactions take place.

Permanent hardness can also be removed by:- 

Treatment with washing soda (sodium carbonate):-  Washing soda reacts with soluble calcium and magnesium chlorides and sulphates in hard water to form insoluble carbonates.

  • Sodium carbonate is water-soluble in nature and hence, adds a large number of carbonate ions to the water.
  • Because of this, the calcium ions come from hard water and the carbonate ions from sodium carbonate.

Question 187

Which of the following is NOT a primary pollutant?

  1. AOption (a)

    Carbon monoxide

  2. BOption (b)

    Volatile organic compunds

  3. COption (c)

    Nitrogen Oxides

  4. DOption (d)

    Ground level ozone

View answer & explanation

Correct answer

Answer: (d)D.

Ground level ozone

Why this answer is correct

Concept-

  • Pollution is any undesirable change in physical, chemical, or biological characteristics of air, land, water or soil.
  • Pollution can be natural or man-made.
  • Natural pollution comes from natural sources like the release of methane by cattle and paddy fields.
  • Man-made or anthropogenic pollution is the pollution caused by human activities like sewage effluents, pesticides.
  • In order to control environmental pollution, the government of India has passed the environmental act, 1986.

Explanation-

  • Primary pollutants are Pollutants that are emitted directly from identifiable sources, either from natural hazardous events like dust storms, volcanoes, etc, or from human activities like burning of wood, coal, oil in homes or industries or automobiles, etc.
  • The important primary air pollutants are:
  • Oxides of sulfur, particularly sulfur dioxide (SO2).
  • Oxides of carbon like carbon monoxide (CO) and carbon dioxide (CO2), particularly carbon monoxide (CO).
  • Oxides of nitrogen, like NO, NO2, NO3 (expressed as NOx).
  • Volatile organic compounds, mostly hydrocarbons.
  • Suspended particulate matter (SPM).

Therefore ground-level ozone is not a primary pollutant.

Additional InformationSecondary pollutant

  • These primary pollutants often react with one another or with water vapour, aided and abetted by the sunlight, to form entirely a new set of pollutants, called the secondary pollutants.
  • These are the chemical substances, which are produced from the chemical reactions of natural or anthropogenic pollutants or due to their oxidation, etc., caused by the energy of the sun.
  • The important secondary pollutants are-
  • Sulphuric acid (H2SO4), Ozone (O3), Formaldehydes and, Peroxy-acyl-nitrate (PAN), etc.

Question 188

Eichhornia crassipes is also known as-

  1. World's most problematic aquatic weed
  2. Terror of Bengal

Choose the correct code-

  1. AOption (a)

    Both 1 and 2

  2. BOption (b)

    Neither 1 nor 2

  3. COption (c)

    Only 2

  4. DOption (d)

    Only 1

View answer & explanation

Correct answer

Answer: (a)A.

Both 1 and 2

Why this answer is correct

The correct option is 1.

Key Points

  • Eichhornia crassipes is also called as water hyacinth.
  • Eichhornia crassipes, the world’s most problematic aquatic weed, is also called the ‘Terror of Bengal’.
  • Because they grow faster than our ability to remove them.
  • It grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body.
  • It is a beautiful mauve-colored flower.
  • These plants which were introduced into India for their lovely flowers have caused havoc by their excessive growth by causing blocks in our waterways.

Important Points 

  • Eutrophication is the gradual increase in the biomass of phytoplankton resulting in 'algal blooms' due to an increase in the concentration of phosphorus, nitrogen, and other plant nutrients in an ageing aquatic ecosystem such as a lake.

Additional Information

  • Lantana Camara is a flower-bearing shrub.
  • Parthenium hysterophorus is a flowering plant species.

Question 189

Which of the following statements is NOT true?

  1. Plant eating animals release a large amount of methane in the atmosphere.
  2. Industrialization and urbanization has lead to release of gases, such as CO2, CH4 and N2O into the atmosphere.

Choose the correct code.

  1. AOption (a)

    Neither 1 nor 2

  2. BOption (b)

    Only 2

  3. COption (c)

    Both 1 and 2

  4. DOption (d)

    Only 1

View answer & explanation

Correct answer

Answer: (a)A.

Neither 1 nor 2

Why this answer is correct

The correct option is 1.

Explanation-

Statement 1

  • Livestock(cows and bogs) release a significant amount of methane.
  • Methane-producing bacteria are called methanogens.
  • Methanogens are found in the gut of ruminants.
  • Methanogens are primarily responsible for methane.
  • Methane is a gas found in coal mines and marshy places.

Therefore plant-eating animals release a large amount of methane into the atmosphere.

Statement 2

  • Industrialization contributes to negative environmental externalities, such as pollution, increased greenhouse gas emission, and global warming.
  • Greenhouse gases can absorb and emit radiant energy within the thermal infrared range.
  • Some of the major greenhouse gases are water vapor, carbon dioxide, Methane, CFC, etc.
  • Some of the greenhouse effects are global warming, climatic change, sea-level change,
  • The concentration of GHG is gradually increasing in the atmosphere.
  • For example, according to the UN climate change conference bulletin, the concentration of CO2 has increased by 147% in 2018 than that pre-industrial level measured in 1750.
  • Atmospheric methane reached a new high of about 1869 parts per billion (ppb) in 2018 and is now 259% of the pre-industrial level.
  • The concentration of Nitrous oxide 331.1 parts per billion in 2018 which is 123% of pre-industrial levels.
  • So it is clear that the concentration of greenhouse gases is gradually increasing as an effect of industrialization and urbanization.

Therefore Industrialization and urbanization has lead to the release of gases, such as CO2, CH4, and N2O into the atmosphere.

Question 190

Which of the following statements is true?

  1. AOption (a)

    Ozone is formed by the action of the UV rays on atomic oxygen at the mesosphere.

  2. BOption (b)

    Ozone is formed by the action of the UV rays on molecular oxygen at the stratosphere.

  3. COption (c)

    Ozone is formed by the action of the UV rays on molecular oxygen at the mesosphere.

  4. DOption (d)

    Ozone is formed by the action of the UV rays on atomic oxygen at the stratosphere.

View answer & explanation

Correct answer

Answer: (b)B.

Ozone is formed by the action of the UV rays on molecular oxygen at the stratosphere.

Why this answer is correct

Explanation:

Ozone is a gas that is present naturally within Earth’s atmosphere. It is formed of three oxygen atoms (O3).

  • Ozone can be formed from diatomic oxygen. The UV radiations split apart molecular oxygen into free oxygen (O) atoms. These oxygen atoms combine with molecular oxygen to form ozone.

Important Points

  • The ozone layer is important for mankind as it acts as a shield absorbing ultraviolet radiation from the sun.
  • UV rays are highly injurious to living organisms. Hence it is important to maintain the ozone layer, but some of the ozone-depleting substances continuously degrade ozone and makes its maintenance very challenging.
  • The Ozone-depleting substances are CFCs (chlorofluorocarbons),  carbon tetrachloride (CCl4), N2O, Methane, CO2, methyl bromide (CH3Br), etc.​

Additional Information

  • The ozone layer is found in the upper part of the atmosphere called the stratosphere.
  • It acts as a shield absorbing ultraviolet radiation from the Sun.
  • UV rays are highly injurious to living organisms since the DNA and proteins of living organisms preferentially absorb UV rays, and it's high energy breaks the chemical bonds within these molecules.
  • The thickness of the ozone in a column of air from the ground to the top of the atmosphere is measured in terms of Dobson units (DU).
  • Ozone gas is continuously formed by the action of UV rays on molecular oxygen and is also degraded into molecular oxygen in the stratosphere.
  • The Montreal Protocol is an international treaty, was agreed on 16th September 1987, and entered into force on 1st January 1989, designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.
  • International Day for the preservation of Ozone Layer is celebrated on 16th September every year.

Teaching Methodology (10 questions)

Question 191

Which of the following statements is incorrect?

  1. AOption (a)

    Natural law explains things, but do not describe them.

  2. BOption (b)

    Hypothesis is an educated guess based on the observation.

  3. COption (c)

    Scientific facts are believed to be dependent of the observer.

  4. DOption (d)

    Theory is an accepted hypothesis.

View answer & explanation

Correct answer

Answer: (c)C.

Scientific facts are believed to be dependent of the observer.

Why this answer is correct

Scientific facts are universally regarded as being independent of the observer: regardless of who conducts a scientific experiment, the outcomes are agreed upon by all observers. Science has its own point of view. Science is a way of life, not just a collection of observations, experiments, and analyses. Science is a corpus of information that grows as a result of the investigation process.

Hint

  • Natural law is an ethical and philosophical framework that claims humans have inherent values that guide their reasoning and actions. In philosophy, natural law is a theory of right or justice that is universal to all humans and is drawn from nature rather than from social standards, or positive law. Natural law describes but does not explain things.
  • A hypothesis is a statement about the natural world that may be proven or disproven by observations or tests. Hypotheses must be testable and falsifiable in order to be deemed scientific. A scientific hypothesis is a theory that can be tested to explain a natural phenomena. The scientific method's first building block. It's often referred to as a "informed estimate" based on past experience and observation. While this is correct, a hypothesis is more reliable than a guess.
  • The evidential value of an observation is regarded to be proportionate to how sensitive it is to the study topic. According to the scientific method, which is based on facts collected via repeated measurements. It is wrong to suppose that scientific facts are based on the observations of others.
  • A hypothesis is a presumption formed for the purpose of testing before any research has been completed. A theory, on the other hand, is a collection of principles that may be used to explain occurrences that have already been proven via evidence. The distinction between a hypothesis and a theory may be seen here. A hypothesis is developed in scientific reasoning before any relevant investigation is completed. A hypothesis, on the other hand, is evidence-based: it's a concept developed to explain facts that have already been shown by data.

Additional Information

  • Science has its own point of view. Science is a way of life, not just a collection of observations, experiments, and analyses. Science is a corpus of information that grows as a result of the investigation process. Scientific truths are widely accepted as being independent of the observer. Regardless of who conducts a scientific experiment, all observers agree on the result. Scientists gather and produce empirical data to get a large portion of the evidence they employ. Observations have always had a specific place in the epistemology of science, according to science philosophers. The 'tribunal of experience' passes judgement on scientific ideas and theories through observations.
  • It has long been considered that an observation's evidentiary value is determined by how sensitive it is to whatever it is meant to explore. However, this is contingent on the sufficiency of any theoretical assertions on which its sensitivity may be predicated. For example, we can contest the use of a specific thermometer reading to support a temperature prediction for a patient by questioning theoretical claims about whether a reading from a thermometer like this one, used in the same way under similar conditions, should accurately indicate the patient's temperature to count in favor of or against the prediction.

Now we can come to a conclusion. This assertion is incorrect since scientific facts are thought to be contingent on the observer.

Question 192

Which of the following is not a nature of science?

  1. AOption (a)

    Science is not for everybody.

  2. BOption (b)

    Science is both a body of knowledge and a process.

  3. COption (c)

    Science is a community enterprise.

  4. DOption (d)

    Science is a global human endeavor.

View answer & explanation

Correct answer

Answer: (a)A.

Science is not for everybody.

Why this answer is correct

When we talk about the nature of science, we're talking about the unique features, beliefs, and assumptions that scientific knowledge is built on, as well as how science is formed.

Important Points

  • "Science is the human creation that strives to describe the events and situations that occur or exist within our natural environment with ever-increasing precision," according to John Woodbourn and E.O. Osbourn. Science is both a private and public activity. It is distinguished by the individual's active creative participation. Simultaneously, societal conditions and needs have an impact on scientific advancement. It is not in the essence of science that science is not for everyone.
  • Science is both a corpus of information (what we already know) and a method of getting new knowledge (via observation and experimentation—testing and hypothesizing). Science is both a corpus of knowledge and an ongoing activity. Because it is a system of obtaining information via observation and experimentation to describe many natural processes around us, it is both a body of knowledge and a continual continuing activity.
  • In many respects, science is a communal endeavor. Individuals working in their garages or laboratories can accomplish a lot, but science is becoming increasingly collaborative. Science necessitates technology that isn't always available in a single laboratory or institution. And science needs information that is frequently beyond the scope of a single person's ability.
  • "The character of researchers' discoveries is influenced by their backgrounds, theoretical commitments, and fields of study." This demonstrates the importance of who conducts science. The science that is done is influenced by scientists' personal experiences, attitudes, and views, as well as what is going on in the world around them.

Additional Information

  • Scientific Knowledge Assumes Order and Consistency in Natural Systems; Science Is a Human Endeavor, and Questions About the Natural and Material World are addressed by science.
  • Science has been defined as a collection of scientific knowledge. Facts, concepts, and hypotheses that are prone to change and mistake make up this corpus of knowledge. Scientific information comes in a variety of forms. Facts. Concepts, principles, and laws are all things that have to do with concepts, principles, and laws.
  • Scientific Knowledge Assumes Order and Consistency in Natural Systems; Science Is a Human Endeavor, and Questions About the Natural and Material World are addressed by science. It entails a series of interconnected steps: observation, searching for regularities and patterns, formulating hypotheses, developing qualitative or mathematical models, deducing their consequences; verification or falsification of theories through observations and controlled experiments, leading to the principles, theories, and laws that govern the physical world.
  • Science's rules are seldom regarded as absolute, unchanging facts. Even science's most established and universal rules are always considered provisional, open to change based on fresh observations, tests, and analysis.

As a result, we might conclude that science is not for everyone is not a nature of science.

Question 193

For a child the concept of natural laws becomes almost fully developed by the age of-

  1. AOption (a)

    12 years

  2. BOption (b)

    6 years

  3. COption (c)

    10 years

  4. DOption (d)

    8 years

View answer & explanation

Correct answer

Answer: (a)A.

12 years

Why this answer is correct

The word "natural law" has a lot of connotations. It can relate to both a moral and a legal theory, although the basic statements of the two are logically separate. It has nothing to do with the natural rules that science seeks to describe. The moral principles that govern individual interactions, according to natural law moral theory, are objectively drawn from the nature of human beings and the nature of the universe in some way. While conceptually separate from natural law legal theory, the two interact. Natural law is an ethical and philosophical framework that claims that humans have inherent values that guide their reasoning and actions.

Key Points

  • Natural law is the concept that there are laws that exist in nature that exist independently of whether or not people exist or acknowledge them. Unlike other types of legislation (known as positive laws) that have been agreed upon by society, such laws would be handed to everyone and could not be overturned.
  • Natural law is credited to Aristotle as its founder. Nature, according to his thinking, created the entire world. He separates man's life into two parts: first, that he is a god-created creation, and second, that he is gifted with active reason, allowing him to develop his own will. This argument, he claims, may be used to identify the principle of natural justice.
  • The capacity to "think more logically and methodically about abstract concepts and hypothetical occurrences" is defined as the final stage in Piaget's cognitive development. By the age of 12, a child's understanding of natural rules is nearly complete. It is time to absorb knowledge with zeal and be prepared.
  • Natural law is essential because it regulates today's moral, political, and ethical institutions. It has been used to explore and discuss human nature and has a long history in political and philosophical thinking. Natural law, for example, presupposes that everyone agrees that murdering another person is immoral and that the punishment for killing another person is appropriate.

Additional Information

  • Late childhood lasts from the age of six to roughly twelve and a half to thirteen years, when sexual maturity is reached. Children exhibit considerable negativism throughout this time, and their quest for independence causes them to seldom heed their parents. The youngster starts school and learns the fundamentals of information that will help him or her succeed as an adult. Children of this age 'crowd together or 'gang LIP,' receiving the moniker 'gang age.'
  • During this period, children learn a variety of talents. Boys and girls have different abilities in these areas. Self-help abilities such as eating, dressing, bathing, and grooming are practically as good as those of an adult, and need very little focus.
  • Helping others is one of the social skills. Cleaning and assisting with everyday duties at home, as well as assisting the instructor at school and sharing responsibilities with peers at play, are significant accomplishments for the youngster.
  • Writing, reading, drawing, painting, clay modelling, and crayoning talents improve in school. Throwing and catching the ball, as well as bicycling, skating, and swimming, are all developed via play. Girls excel in fine motor skills such as painting and embroidery, whereas boys excel at coarse motor abilities such as throwing a ball, kicking a football, or jumping.

By the age of 12 years old, a child's understanding of natural laws is nearly complete. The ages 9 to 12 are considered late childhood.

Question 194

In which of the following time did the concept of Non-Formal Education come into picture in India?

  1. AOption (a)

    Late 60s and early 70s

  2. BOption (b)

    Late 50s and early 60s

  3. COption (c)

    Late 80s and early 90s

  4. DOption (d)

    Late 70s and early 80s

View answer & explanation

Correct answer

Answer: (a)A.

Late 60s and early 70s

Why this answer is correct

The concept of Non-Formal Education (NFE) in India emerged in the late 1960s and early 1970s as a response to the need for alternative educational approaches to address the educational gaps and provide opportunities for learning to a diverse range of individuals who were not able to access or benefit from the formal education system.

Key Points

  • In the post-independence period, it became apparent that the formal education system in India was not reaching everyone.
  • Large sections of the population, including adults, working individuals, out-of-school children, and marginalized communities, were excluded from formal education due to various socio-economic and geographical factors.
  • The late 1960s and early 1970s marked a shift in educational policy and thinking.
  • There was a growing recognition that education should not be limited to schools and classrooms but should be tailored to meet the diverse educational needs of different groups in society.

Hence, we can conclude that the concept of Non-Formal Education (NFE) came into the picture in India during the late 60s and early 70s.

Question 195

In the management of group-learning, which kind of grouping might lead to the labelling of few students as bright and few as weak?

  1. AOption (a)

    Random student grouping

  2. BOption (b)

    Grouping by students' choice

  3. COption (c)

    Grouping students by ability

  4. DOption (d)

    Grouping students by interest

View answer & explanation

Correct answer

Answer: (c)C.

Grouping students by ability

Why this answer is correct

The objective of the learning activity determines whether or not students of comparable aptitude should form groups. Students prefer to learn in groups of their classmates and friends (homogeneous groups) if given the option, but they equally value getting to know and learning from other students. This necessitates our faith in students' ability to make sound judgments and holding them accountable for adhering to group learning norms.

Important Points

  • The teacher circles the room, questioning students on the conclusions gained from their data while groups of students execute experiments. Grouping pupils by ability may result in the labelling of a few students as brilliant and a few as deficient in the administration of group learning.
  • Students are given the opportunity to ponder and demonstrate their reasoning. By attempting to discover their sources of evidence, the teacher will have a greater knowledge of their students' issues and will be able to adjust their teaching accordingly, leading to improved grasp of the topic.
  • A group is a collection structure of two or more persons that interact and are interdependent, have similar motives, a set of role connections among its members, and have rules that govern their conduct.
  • Both students and instructors have found group work to be useful. Ability grouping (also known as tracking) is defined by the National Education Association as "the technique of arranging kids in the classroom depending on their talents." Ability grouping, as contrast to cooperative learning, allocates students to homogenous groups or classrooms based on their skills.

Additional Information

  • Students who have mastered certain principles in a topic can become tutors and educate the other students in the group. Furthermore, the weak and hesitant kids may be unable to move as quickly as the case moves (just) a few students from one group to another. The objective of the learning activity determines whether to establish groups with students of similar or mixed aptitude.
  • Groups differ from other types of gatherings of individuals. Groups are defined by mutual dependency, duties, status, and expectations. Groups are self-contained systems made up of two or more people. People join organizations for a variety of reasons, including security, status, self-esteem, fulfilment of psychological and social needs, goal attainment, and knowledge and information.
  • The creation of groups is aided by proximity, resemblance, and shared reasons and goals. In general, group effort yields positive results. However, groupthink may arise in cohesive and homogenous groups. There are several forms of groups, such as primary and secondary, official and informal, ingroup and outgroup.

As a result, we may conclude that grouping students by ability kind of grouping may result in the labelling of a few students as brilliant and a few students as poor in the administration of group-learning.

Question 196

Which chapter of the Right to Education Act, 2009 provides for the Protection of Right of Children?

  1. AOption (a)

    VIII

  2. BOption (b)

    VI

  3. COption (c)

    V

  4. DOption (d)

    VII

View answer & explanation

Correct answer

Answer: (b)B.

VI

Why this answer is correct

A child's right to a free and compulsory education is guaranteed. —1 [(1) Every child aged six to fourteen years, including a child described in section 2 clauses (d) or (e), has the right to free and obligatory education in a neighborhood school until the conclusion of his or her primary education.]

 Key Points

  • Every kid aged 6 to 14 has a right to a free and obligatory education. This is spelled forth in Article 21A of the 86th Constitutional Amendment Act. This change is being implemented through the Right to Education Act. All students would get a free education from government schools, which will be run by School Management Committees (SMC). At least 25% of the pupils enrolled in private schools must be admitted free of charge. A National Commission for Elementary Education will be established to oversee all elements of primary education, including quality.
  • The Protection of Children's Rights is included in Chapter VI of the Right to Education Act, 2009. SCHOOLS' AND TEACHERS' RESPONSIBILITIES 12. The extent to which schools are responsible for providing free and compulsory education to students.
  • The RTE Act's major goal is to ensure that every kid in India, regardless of their economic or caste background, obtains a quality elementary education, including those who are forced to leave out.
  • The state and federal governments are legally obligated to carry out a child's fundamental rights under this Act (as per Article 21 A of the Constitution). The Act establishes defined requirements for student-to-teacher ratios, which is a critical notion in providing high-quality education.

Additional Information

  • Children have the right to free and obligatory education in a local school until they complete elementary school, according to the RTE Act. 'Free' indicates that no kid will be required to pay any fees, charges, or expenditures that would prohibit him or her from continuing and finishing a primary education.
  • All Indian children aged 6 to 14 are entitled to free and compulsory schooling. Until the end of primary school, no kid shall be held back, expelled, or compelled to pass a board examination.
  • If a kid beyond the age of six has not been accepted into any school and has not completed his or her elementary education, he or she will be placed in a class that is appropriate for his or her age. However, if a kid is placed straight in a class that is appropriate for his or her age, he or she has the right to receive special instruction within the time restrictions that may be specified in order to be on level with others. Furthermore, a kid enrolled to elementary school must be entitled to free education until the end of elementary school, even if the child reaches the age of 14.
  • Proof of age for admission: A child's age for admission to primary school should be established on the basis of a birth certificate issued in compliance with the Provisions of Birth, Deaths, and Marriages Registration Act 1856, or such other document as may be required. A child's admittance to a school should not be refused due to a lack of proof of age. A certificate will be given to each child who completes elementary school. For a constant student–teacher ratio, a call must be made.

In all private schools, there will be a 25% reserve for economically disadvantaged areas in Class I admissions.

  • Education must be improved. Within the next five years, school instructors will be required to get a professional degree or risk losing their jobs.

Every three years, school infrastructure must be upgraded (if there is a problem), otherwise recognition will be revoked.

The state's and the federal government's financial responsibilities will be shared.

As a result, we may infer that the VI th chapter of the Right to Education Act of 2009 protects children's rights.

Question 197

Which of the following organisation has taken the stand 'Discriminatory behaviors take many forms, but they all involve some form of exclusion or rejection?

  1. AOption (a)

    MADRE

  2. BOption (b)

    Equality Now

  3. COption (c)

    WHO

  4. DOption (d)

    UNO

View answer & explanation

Correct answer

Answer: (d)D.

UNO

Why this answer is correct

Discrimination is the act of establishing unwarranted distinctions between individuals based on the groups, classes, or other categories to which they belong or are thought to belong. Discrimination can occur based on race, gender, age, religion, sexual orientation, and other factors. Individuals or groups are unfairly treated in ways that are worse than other people on the basis of their real or perceived membership in specific groups or social categories, which is known as discrimination. It entails denying members of one group access to chances or advantages enjoyed by members of a different group.

Key Points

  • MADRE's main focus is on global women's rights, including assisting women in war, women battling climate change, women who have been sexually abused, and women who have been victims of human trafficking.
  • Equality Now is a non-profit organization that advocates for the protection and advancement of women's and girls' human rights. It was created in 1992.
  • WHO's main responsibility is to coordinate international health within the UN system and to lead partners in global health responses. The major goal of the WHO is "the attainment of the highest attainable level of health by all peoples." It has six regional offices and 150 field offices globally, with its headquarters in Geneva, Switzerland.
  • Discriminatory behaviours take numerous shapes, but they always include some type of exclusion or rejection,' according to the UN. Racism, racial discrimination, xenophobia, and related intolerance occur on the basis of race, colour, descent, or national or ethnic origin, and that victims can face multiple or aggravated forms of discrimination based on other factors such as sex, language, religion, political or other beliefs, social origin, property, birth, or other factors.

 Additional Information

  • The United Nations (UN) is an international organisation that was established to maintain worldwide peace and aid in the development of international cooperation rules. The United Nations Organizations (UNO) is how people refer to the UN (UNO).
  • Discrimination has obvious implications for those who are discriminated against, but it also has indirect and long-term consequences for society. People are robbed of freely achieving their full potential for themselves and society in a society where prejudice is allowed or accepted.
  • The United Nations, as the world's only genuinely universal global organisation, has emerged as the most important platform for addressing concerns that cut beyond national borders.
  • The United Nations has a set of principles that states that all member countries are sovereign and equal, that they must respect the rights of other nations, that they must resolve their differences peacefully and without threat or contention, and that they must support the organisation in all of its endeavours.

As a result, the United Nations has served as a foundation for a number of international organisations to adopt policies and programmes engaging indigenous peoples. 'Discriminatory behaviours come in a variety of forms, but they all include some type of exclusion or rejection,' according to the United Nations.

Question 198

Which factors affect learning?

  1. Maturation
  2. Readiness to learn
  3. Learning environment

Choose the correct code.

  1. AOption (a)

    Only 1 and 3

  2. BOption (b)

    Only 1 and 2

  3. COption (c)

    1, 2 and 3

  4. DOption (d)

    Only 2 and 3

View answer & explanation

Correct answer

Answer: (c)C.

1, 2 and 3

Why this answer is correct

Learning is the process of gaining new information, skills, values, attitudes, and preferences via the acquisition of new understanding, knowledge, actions, and abilities. Humans, animals, and certain robots all have the potential to learn, and even plants have been shown to have some form of learning.

Important Points

  • The process of obtaining complete or advanced development is known as maturation. To put it another way, maturation is the process of becoming older (or maturing). The term is frequently used to describe a person's physical maturation or the beginning of more adult behaviour.
  • Learning readiness refers to a student's ability to learn, taking into account a variety of aspects such as circumstance and environment. A student's low willingness to learn might be due to harsh personal circumstances or a lack of emotional or physical development.
  • Learning materials and technology, instructional methods, learning styles, and links to societal and global settings are all included in the phrase learning environment.
  • Maturity, readiness to learn, and learning environment are all elements that influence learning.

Additional Information

  • Maturity is described as "growth that occurs on a regular basis under a variety of environmental settings," and it has a significant impact on our learning. Maturation is defined as steady growth in a person that occurs without the need of particular stimuli such as training or practise. Only once a certain level of development has been attained is learning feasible. Only when a certain level of maturity is reached can exercise and training become productive.
  • Throughout many respects, being prepared means having the abilities necessary to deal with what lies ahead and to both learn from and contribute to what is taking place. It indicates you've got the abilities you'll need not just to survive, but also to thrive in your next learning opportunity.
  • An engaged learning environment has been demonstrated to improve students' attention and focus, enhance meaningful learning experiences, support greater levels of student achievement, and push students to exercise higher-level critical thinking abilities, according to research.

A child's learning is influenced by a variety of psychological characteristics including IQ, personality, attitude, interest, and aptitude. Apart from them, motivation, self-concept, and preparedness are all important, and children often learn to read without much instruction. As a result, learning is influenced by maturity, readiness to learn, and learning environment elements.

Question 199

In which year did the "USSR Experts of UNESCO Planning Mission" visit India on technical assistance project?

  1. AOption (a)

    1963

  2. BOption (b)

    1975

  3. COption (c)

    1971

  4. DOption (d)

    1967

View answer & explanation

Correct answer

Answer: (a)A.

1963

Why this answer is correct

The United Nations Educational, Scientific, and Cultural Organization (UNESCO) is a non-governmental organisation that promotes education, science, and culture across the world. It is a UN member. UNESCO was established in 1946 with the goal of rebuilding schools, libraries, and museums that were destroyed during WWII in Europe.

Important Points

  • In 1963, UNESCO planning mission specialists from the USSR paid a visit to India and advised improvements in science and mathematics education.
  • UNESCO has funded several initiatives and programmes in India, as well as providing technical help to special missions and hosting meetings and seminars.
  • Technical assistance (TA) is a type of ADB assistance that makes developing programs and projects easier to plan, finance, and implement. It assists developing member countries (DMCs) in strengthening their capacities and making better use of their development funds.
  • The "USSR Experts of the UNESCO Planning Mission" visited India in 1963 to investigate the execution of technological assistance programmed. After working on the situation from December 3, 1963 to March 10, 1964, they made suggestions on many topics concerning scientific teaching in secondary schools. The team produced three papers that provided a comprehensive overview of the state of science and mathematics education in India and offered recommendations for improvement.

Additional Information

  • UNESCO promotes international collaboration in the fields of education, research, culture, and communication among its 193 Member States and 6 Associate Members. UNESCO's confidence in the public library as a living force for education, culture, and knowledge, as well as a critical agent for promoting peace and spiritual well-being via men and women's minds. As a result, UNESCO urges national and local governments to foster the establishment of public libraries and to actively engage in it.
  • On a technical support project, the "USSR Experts of the UNESCO Planning Mission" came to India. The experimental programme was developed based on the report of the Planning Mission.

As a result of the above, we can understand the "USSR Experts of the UNESCO Planning Mission" visited India in 1963 on a technical support initiative.

Question 200

Which day is celebrated as the International Women's Day?

  1. AOption (a)

    March 6

  2. BOption (b)

    March 7

  3. COption (c)

    March 5

  4. DOption (d)

    March 8

View answer & explanation

Correct answer

Answer: (d)D.

March 8

Why this answer is correct

International Women's Day is an opportunity to celebrate progress toward gender equality and women's empowerment, as well as to critically reflect on those achievements and seek for greater momentum toward gender equality globally. It's a day to acknowledge women's outstanding achievements and to unite as a global force to promote gender equality.

Key Points

  • At the start of the twentieth century, labour movements in North America and Europe sparked the creation of International Women's Day. The Socialist Party of America established the first National Woman's Day on February 28, 1909, to commemorate the 1908 garment workers' strike in New York, during which women protested against poor working conditions. On the final Sunday in February of 1917, Russian women opted to protest and strike under the banner "Bread and Peace" (which fell on 8 March on the Gregorian calendar). Women's suffrage was eventually granted in Russia as a result of their efforts.
  • The United Nations Charter(link is external) was the first international accord to recognise the ideal of gender equality in 1945. In 1975, during International Women's Year, the United Nations commemorated the first official International Women's Day on March 8. Two years later, in December 1977, the United Nations General Assembly passed a resolution designating a United Nations Day for Women's Rights and International Peace, to be marked by Member Countries on any day of the year in line with their historical and national traditions.
  • International Women's Day is a worldwide celebration of women's achievements in the fields of social, economic, cultural, and political empowerment. The day also serves as a rallying cry for achieving gender parity sooner rather than later. Women's accomplishments are being celebrated and rallies for women's equality are taking place all around the world.

Additional Information

  • International Women's Day (IWD), which takes place every year on March 8th, is one of the most important days of the year to:

women's accomplishments should be honored, increase awareness about women's equality push for faster gender parity provide funds for women's charities.

  • International Women's Day (March 8) is a worldwide celebration of women's social, economic, cultural, and political accomplishments. The day also serves as a rallying cry for achieving gender parity sooner rather than later.
  • In 1910, during the International Conference of Working Women in Denmark, a woman named Clara Zetkin proposed a special day of honor. The inaugural International Women's Day was observed in 1911 by Austria, Denmark, Germany, and Switzerland.
  • The first reported Women's Day commemoration, dubbed "National Woman's Day," took place on February 28, 1909, in New York City, and was organised by the Socialist Party of America at activist Theresa Malkiel's suggestion.

As a result, the International Women's Day is observed on March 8th. This is a worldwide celebration of women's achievements in the fields of social, economic, cultural, and political empowerment.

200 questions in the full paper