RRB NTPC CBT-I Official Paper (Held On: 10 Feb 2021 Shift 2) (Previous Year Paper)

The correct answer is InSight Mission.

Key Points

• Mars rover mission by NASA's Mars exploration program is planned to launch in 2020.
• The Mars 2020 InSight Mission mission is part of NASA's Mars Exploration Program.
• It was a long-term effort of robotic exploration of the Red Planet.
• The Mars 2020 mission launched on July 30, 2020.
• It's motive is to search for signs of ancient microbial life.
• Mars rover mission by NASA's Mars exploration program will also gather rocks and Soil.
• It will include a testing method for producing oxygen from the Martian atmosphere.
• The Mars 2020 spacecraft uses a guided entry, descent, and landing system.

Additional Information

• NASA:
• The full form of NASA is the National Aeronautics and Space Administration.
• It is an independent agency of the US federal government.
• It is responsible for the civil space program, aeronautics research, and space research.

Given:

Total percentage of voters votes = 75%

Invalid votes = 2%

A candidate got votes = 9261 votes = 75% of valid votes

Formula Used:

Percentage = $\frac{Initail \space value}{Final \space value}\times100$

Calculation:

Let the total number of votes = x

A candidate got votes = 9261

According to the question,

⇒ 75% of valid votes = 9261

⇒ Valid votes = $\frac{(9261 \times 100)}{75}$ = 3087 x 4 = 12348

⇒ Total votes enrolled = 75% of x = $\frac{75x}{100}$

Invalid votes declared = 2% of total votes

⇒ Valid votes percentage = 100 - Invalid votes = 100 - 2 = 98% votes are valid = $\frac{98}{100}\times \frac{75x}{100}$

So we can say,

⇒ $\frac{98}{100}\times \frac{75x}{100}$ = 12348

⇒ Total votes(x) = 1.68 x 10000 = 16800

Hence, The total votes enrolled in the election cast their votes is 16800

The correct answer is Gujarat.

Key Points

• It produces 29.78 percent of the total cotton production of India.
• It is also called ‘Cottonpolis of India’.
• India is the world’s largest producer of cotton.
• The states of Gujarat, Maharashtra, Andhra Pradesh, Haryana, Punjab, Madhya Pradesh, Rajasthan, Karnataka, and Tamil Nadu are the major cotton-producing areas in India.
• Nearly two-thirds of cotton production in India comes from the states of Maharashtra, Gujarat, Andhra Pradesh, and Telangana - collectively known as the Cotton Basket of India.
• The United States Department of Agriculture (USDA) pegs India's cotton production at 29 million bales in 2019-20.

Additional Information

• Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus Gossypium in the mallow family Malvaceae.
• The fiber is almost pure cellulose and can contain minor percentages of waxes, fats, pectins, and water.
• Cotton is a natural fiber that grows on a plant.
• It is both a food and fiber crop, and the plant is a leafy, green shrub related to the hibiscus species of plants.
• There are up to 52 species of cotton in the Gossypium genus.

The correct answer is Plasmodium.

Key Points

• Malaria
• Microorganisms of the Plasmodium groups are responsible for causing malaria.
• Only Anopheles mosquitoes with the infection can transmit it through bites.
• The parasites in the mosquito's saliva are transferred into the victim's blood through the bite.
• To mature and reproduce, the parasites travel to the liver.
• Humans have the ability to contract and spread five different Plasmodium species.
• P. falciparum is the most common cause of malaria-related deaths, while P. vivax, P. ovale, and P. malariae typically cause a less severe form of the disease.
• P. knowlesi rarely infects humans with disease
• Fever, exhaustion, nausea, and headaches are among the typical symptoms of malaria.
• Seizures, a coma, or even death have been known to occur in extreme cases.

Additional Information

• Plasmodium
• An obligate parasite of insects and vertebrates, Plasmodium is a genus of unicellular eukaryotes.
• In the course of their life cycles, Plasmodium species develop in blood-feeding insect hosts before injecting parasites into vertebrate hosts during a blood meal.
• Prior to entering the bloodstream to infect red blood cells, parasites develop within a vertebrate body tissue (often the liver).
• Malaria may result from the resulting depletion of host red blood cells.
• In the majority of cases, mosquitoes feed on blood, so some parasites picked up during this infection are picked up by them and the life cycle is continued.
• The large group of parasitic eukaryotes known as Apicomplexa includes Plasmodium.

The correct answer is Germany

Key Points

• Indian Defence Minister Shri Rajnath Singh visited Moscow in the last week of June to attend the Victory Parade that commemorated the 75^th anniversary of the Second World War.
• The Parade was organised to honour the heroism and sacrifices of the Russian and other friendly forces.
• Every year, Russia celebrates Victory Day on May 9 to commemorate the Soviet Union's victory over Germany's Nazi forces in World War II.
• The Russian military holds a parade at Moscow's Red Square and in other cities to mark the event.

Additional Information

• Germany. Events in Berlin occur on 8 May to commemorate those who fought against Nazism in the German Resistance and lost their lives in World War II.
• In 2020, a regional holiday in Berlin occurred on 8 May to mark the 75^th anniversary of surrender.

Given:

A can do a piece of work alone in 32 days

Together with B, she can do the work in 24 days

C alone can do the work in 64 days

Formula Used:

Efficiency = $\frac{Work \space done}{Number\space of\space days}$

Calculation:

A can the work = 32 days

⇒ A does work in 1 day = $\frac{1}{32}$

Similarly,

Together with B, she does the work = 24 days

⇒ A + B = 24

Amount of (A + B) together work in one day

⇒ $\frac{1}{32}+\frac{1}{B}=\frac{1}{24}$

⇒ $\frac{1}{B}=\frac{1}{24}-\frac{1}{32}=\frac{4-3}{96}=\frac{1}{96}$

C can do the work = 64 days

⇒ C does work in 1 day = $\frac{1}{64}$

B and C together can work in one day

⇒ $\frac{1}{96}+\frac{1}{64}=\frac{2+3}{192}=\frac{5}{192}$

⇒ B and C together complete the work in = $\frac{192}{5}$ = 38$\frac{2}{5}$

Hence, B and C together can complete the work in 38$\frac{2}{5}$

Given series: 234, 197, 160, ? , 86, 49

The logic here is:

37 is deducted from the first number to get the next term and so on.

Therefore, '?' will be replaced with '123'.

Hence, the correct answer is option (3).

Given:

A student multiplied a number by $\frac{3}{5}$ instead of $\frac{5}{3}$

Concept Used:

Percentage=$\frac{Error}{Actual\space value}\times100$

Calculation:

Let the number = x

According to the question

⇒ A student multiplied = $\frac{3x}{5}$

⇒ Actual value = $\frac{5x}{3}$

⇒ Error = $\frac{5x}{3}-\frac{3x}{5}=\frac{25x-9x}{15}=\frac{16x}{15}$

⇒ Percentage=$\frac{\frac{16x}{15}}{\frac{5x}{3}}\times100=16\times4=64$

Hence, the error percentage in the calculation is 64%

Given:

The ratio of the two numbers is 3 : 4

HCF = 4

Formula Used:

HCF x LCM = product of two number

Calculation:

Ratio = 3 : 4

⇒ Let the First number = 3x

⇒ Second number = 4x

HCF means common in both the number

⇒ so x = 4

⇒ First Number = 3 x 4= 12

⇒ Second number= 4 x 4= 16

According to the formula,

⇒ HCF x LCM = product of two number

⇒ 4 x LCM = 12 x 16

⇒ LCM = 12 x 4 = 48

Hence, The LCM of the two numbers is 48

Here, the following logic is used:

'SPECTROSCOPY' = 'ESPRCTCOSYOP'

Similarly,

'EXTRAVAGANZA' = 'TEXVRAAAGANZ'

Hence, the correct answer is option (2).

Statement:

Together our mother is very strict about our meals and prepares healthy food for us, she lets us have doughnuts once in a while.

Assumptions:

I. Doughnuts are healthy.

II. Healthy food is prepared by our mother.

Assumption I. Since mother allows us to have doughnuts once in a while, which means they are not healthy. So, this assumption is not followed

Assumption II. Mother is strict about meals and prepares healthy food. So, this assumption is followed.

Therefore, only assumption II is implicit.

Hence, the correct answer is option (3)

The Correct answer is Termite.

Key Points

• Termites are small insects that live in colonies and have distinct castes and feed on wood or other dead plant matter, occurring on every continent except Antarctica.
• Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitidae, within the order Blattodea.
• Although termites cause serious structural damage to properties, they are not known to attack or bite people and pets nor do they pose any serious health concerns.
• Termites can cause significant destruction to structures, they do not pose a direct threat to humans.

Additional Information

• Beneficial insects
• ​Hoverflies.
• Ladybirds.
• Parasitic wasps.
• Butterflies and moths.
• Lacewings.
• Ground beetles.
• Solitary bees (Hymenoptera).

Given;

3.14 × 106

Concept Used:

The number system is defined as the system of expressing the number

Calculation:

⇒ 3.14 x $10^6$ = 3.14 x 1000000 = 3140000

Hence, The value equal to 3140000

Given:

Mean of 100 observation = 40

The standard deviation of 100 observation = 5.1

One observation is taken as 50 instead of 40

Formula Used:

Mean($\overline x$) = $\frac{Sum\space of \space obsvatiom}{Total\space number\space of \space observation}$

$(Standard\space deviation)^2$ = $\frac{\sum x_i^2}{n}-(\overline x)^2$

Calculation:

⇒ $\overline x=\frac{1}{n}\displaystyle\sum_{i=1}^{100} x_i$

⇒ $\displaystyle\sum_{i=1}^{100} x_i=\overline x × n$ = 40 x 100 = 4000

⇒ $(S.D)^2=\frac{\sum x_i^2}{n}-\overline x$

$sum x_i^2=n[(S.D)^2+(\overline x)^2]$ = 100 × [$5.1^2$ + $40^2$} = 100 × (26.01 + 1600) = 162601

Corrected mean=$\frac{1}{n}\displaystyle\sum_{i=1}^{100} x_i$ = 4000 - 50 + 40 = 3990

Corrected $\sum x_i^2$ = 162601 - $50^2$ + $40^2$ = 161701

Corrected mean = $\frac{Sum\space of \space obsvatiom}{Total\space number\space of \space observation}=\frac{3990}{100}$ = 39.9

Corrected $S.D^2$ = $\frac{\sum x_i^2}{n}-(\overline x)^2=\frac{161701}{100}-39.9^2$ = 25

S.D = $\sqrt{25}$ = 5

Hence, The Correct mean and correct deviation are 39.9 and 5

The positional value of alphabets are as follows

Here, the following logic is used

Code = (sum of the positional values of the alphabets) × 3

MOANA

= (13 + 15 + 1 + 14 + 1) × 3

= 44 × 3

= 132

Similarly,   

CROOD

= (3 + 18 + 15 + 15 + 4) × 3

= 55 × 3

= 165 

Hence, the correct answer is option (2).

Given:

$\frac{a}{2}$ = $\frac{b}{3}$ = $\frac{c}{5}$ 

Concept Used:

A ratio is a mathematical tool for the comparison of two quantities.

Calculation:

Let the ratio = k

⇒ $\frac{a}{2}$ = $\frac{b}{3}$ = $\frac{c}{5}$ = k

then,

⇒ a = 2k

⇒ b = 3k

⇒ c = 5k

According to the question,

⇒ $\frac{{a + b + c}}{c}=\frac{{2k+3k+5k}}{5k}=\frac{10k}{5k}=2$

Hence, the value of the above equation is 2

The family chart symbols is as follows

According to the givens statement, we have the family tree as:

Thus, the the boy’s mother is Maternal Aunt to Suresh.

Hence, the correct answer is option(1)

Given:

To find the sum of even natural numbers less than 85

Formula Used:

Sum = $\frac{n[2a+(n-1)d]}{2}$

n = number of term

a = first term

d = difference between the first and second number

Number of term = $\frac{Last\ term - First\ term}{2}+1$

The direct formula for the sum of n even numbers = n(n + 1)

Calculation:

⇒ First even natural number(a) = 2

⇒ Second even natural number = 4

⇒ Difference(d) = 4 - 2 = 2

⇒ Last even natural number = 84

⇒ Number of term = $\frac{84 - 2}{2}+1=\frac{82}{2}+1=41+1=42$

According to the question,

⇒ Sum = $\frac{n[2a+(n-1)d]}{2}=\frac{42[2×2+(42-1)2]}{2}$ = 21(4 + 41 x 2) = 21 × 86 = 1806

Hence, the required sum of even natural numbers is 1806.

Given:

A number, x, when divided by 7 leaves a remainder of 1

Another number y, when divided by 7 leaves a remainder of 2

Formula Used:

Number = Divisor x Quotient + Remainder

Calculation:

According to the question,

Divisor = 7

Let Quotient = k

x = 7k + 1

Let the value of k be 1

So, x = 7k + 1 = 7 x 1 + 1 = 7 + 1 = 8

Similarly,

y = 7k + 2

Let the value of k be 1

So, y = 7k + 2 = 7 x 1 + 2 = 7 + 2 = 9

x + y = 8 + 9 = 17

x + y is divided by 7

17 = 7 x 2 + 3

Hence, when x + y is divided by 7 gives the remainder 3.

Given:

A triangle and a parallelogram are on the same base and between the same parallels

Concept Used:

Two triangles are said to be congruent if their sides have the same length and angles have the same measure

Proof:

Draw BQ parallel to AP to obtain another parallelogram ABQP. Now parallelograms ABQP and ABCD are on the same base AB and between the same parallels AB and PC.

⇒ ar (ABQP) = ar (ABCD)

⇒ △PAB = △BQP

Diagonal PB divides parallelogram ABQP into two congruent triangles

⇒ ar(△BQP) = $\frac{1}{2}$ar(ABQP)

therefore,

⇒ ar(△PAB) = $\frac{1}{2}$ar(ABQP)

So, we can say

⇒ ar(△PAB) = $\frac{1}{2}$ar(ABCD)

Hence,  ar(△PAB) = $\frac{1}{2}$ar(ABCD)

The correct answer is Homi Jehangir Bhabha

Key Points

• Homi Jehangir Bhabha was an Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research.
• Dr. Bhabha established the Atomic Energy Establishment, (AEET), Trombay, Mumbai in January 1954.
• AEET was subsequently renamed Bhabha Atomic Research Centre (BARC).

Additional Information

• ​Vikram Ambalal Sarabhai was an Indian physicist and astronomer who initiated space research and helped develop nuclear power in India. Honored with Padma Bhushan in 1966 and the Padma Vibhushan in 1972. He is regarded as the Father of the Indian Space Program
• Satish Dhawan was an Indian mathematician and aerospace engineer, widely regarded as the father of experimental fluid dynamics research in India.
• Raja Ramanna was an Indian physicist who is best known for his role in India's nuclear program. Ramanna worked under Homi Jehangir Bhabha and later became the director of this program in 1967

The correct answer is China.

Key Points

• Gold mining is a global business with operations on every continent, except Antarctica, and gold is extracted from mines of widely varying types and scale
• At a country level, China was the largest producer in the world and accounted for around 9 percent of total global production

Additional Information

• An estimated 100 metric tons of gold were produced in South Africa. The gold mining industry in South Africa is an important source of employment. India's gold mine production.
• Australia is the second largest gold producer in the world, reaching 390 tonnes per annum. Australia has two of the world's 20 largest gold mines and reserves totaling more than 380 million ounces of gold
• India's gold mine production is just 1.6 tonnes as of 2019 and could rise to 20 tonnes per year, highlights a World Gold Council report on 'Gold Mining in India".

Given:

Selling the article for ₹ 350 - Selling the article for ₹ 340 = 5% Gain

Concept Used:

A percentage is a number or ratio that can be expressed as a fraction of 100

Calculation:

According to the question

⇒ 5% = 350 - 340

⇒ 5% = 10

⇒ 1% = 2

⇒ 100% = 200

Hence, The cost price of the article is ₹ 200.

The correct answer is Cuba

Key Points

• The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects
• With 189 member countries, staff from more than 170 countries, and offices in over 130 locations.
• The World Bank Group is a unique global partnership: five institutions working for sustainable solutions that reduce poverty and build shared prosperity in developing countries.

Additional Information

• The World Bank is run by a president and 25 executive directors, as well as 29 various vice presidents.
• It has 189 and 174 member countries, respectively.
• The U.S., Japan, China, Germany, and the U.K. have the most voting power.
• The bank aims for loans to developing countries to help reduce poverty.

Given:

The greatest four-digit number

Concept Used:

The long division method is used for finding the square root of the number 

Calculation:

⇒ Greatest four-digit number = 9999

⇒ Long division method for 9999

It gives the remainder 198

For making the perfect square we have to subtract the number from the remainder

⇒ Perfect Square = 9999 - 198= 9801

Hence, The Greatest Four Digit perfect square is 9801

Given:

The sum of half, one-third, and one-fifth of a number exceeds the number by 12

Concept Used;

The number system is defined as the system of expressing or writing the numbers

Calculation:

Let the number = x

According to the question

⇒ $\frac{1}{2}$x + $\frac{1}{3}$x + $\frac{1}{5}$x = x + 12

⇒ $\frac{15x+10x+6x}{30}$ = x + 12

⇒ $\frac{31x}{30}$ = x + 12

⇒ 31x = 30x + 360

⇒ 31x - 30x = 360

⇒ x = 360

Hence, The number is 360

Given Equation: 65, 5, 25 = 190

Let's check all the options one by one

Option 1) × , -

Putting signs in place of commas

⇒ 65 × 5 - 25 = 190

⇒ 325 - 25 = 190

⇒ 300 = 190 (which is not possible)

⇒ LHS ≠ RHS 

Option 2) × , +

Putting signs in place of commas

⇒ 65 × 5 + 25 = 190

⇒ 325 + 25 = 190

⇒ 350 = 190 (which is not possible)

⇒ LHS ≠ RHS 

Option 3) +. × 

Putting signs in place of commas

⇒ 65 + 5 × 25 = 190

⇒ 65 + 125 = 190

⇒ 190 = 190

⇒ LHS = RHS 

Option(4) ÷ . × 

Putting signs in place of commas

⇒ 65 ÷  5 × 25 = 190

⇒ 13 × 25 = 190

⇒ 325 = 190 (which is not possible)

⇒ LHS  ≠ RHS 

Only option 3) balances the equation.

Hence, the correct answer is +, ×.

The correct answer is Mission Indradhanush

Key Points

• Mission Indradhanush is a health mission of the Government of India.
• It was launched by Union Health Minister J. P. Nadda on 25 December 2014
• The scheme seeks to drive toward 90% full immunization coverage of India and sustain the same by the year 2022.
• The main objective is to ensure high coverage of children and pregnant women with all available vaccines throughout the country.

Additional Information

• Sukanya Samriddhi Yojana is a Government of India-backed saving scheme targeted at the parents of girl children. The scheme encourages parents to build a fund for the future education of their female children.
• Pradhan Mantri Ujjwala Yojana was launched by Prime Minister of India Narendra Modi on 1 May 2016 to distribute 50 million LPG connections to women of Below Poverty Line families. A budgetary allocation of ₹80 billion was made for the scheme
• Pradhan Mantri Jan Dhan Yojana is a financial inclusion program of the Government of India open to Indian citizens, that aims to expand affordable access to financial services such as bank accounts, remittances, credit, insurance and pensions

Here, the dam and its location are given.

option 1): Tehri dam is in Uttarakhand (not in Maharashtra).

option 2): Sardar Sarovar dam is in Gujarat.

option 3): Hirakud dam is in Odisha.

option 4): Bhakra dam is in Himachal Pradesh.

So, 'Tehri Dam - Maharashtra' is incorrectly matched

Hence, the correct answer is option 1).

Here, we will interchange the signs as given below,

'×' means '-', '÷' means '+', '-' means '÷' and '+' means '×'

Given Equation:  40 × 5 + 10 - 2 ÷ 8

Interchanging the signs and using BODMAS

Interchanging the signs, according to the question,

⇒ 40 - 5 × 10 ÷  2 + 8

⇒ 40 - 5 × 5 + 8

⇒ 40 - 25 + 8

⇒ 48 - 25

⇒ 23

Therefore, the 23 is a value that comes after interchanging the signs.

Hence, the correct answer is option 1).

Given:

Central angle = 60°

Arc = 35 cm

Formula Used:

Radius =$\frac{arc}{angle}$

Calculation:

⇒ Angle(in radian) = 60º = $60\times \frac{\pi}{180}$ = $\frac{\pi}{3}$

⇒ Radius = $\frac{arc}{angle}=\frac{35}{\frac{\pi}{3}}=\frac{105}{\pi}$

Hence, The Radius of the circle is $\frac{105}{\pi}$ cm

The correct answer is Gold Coast

Key Points

• The 2018 Commonwealth Games, officially known as the XXI Commonwealth Games and also known as Gold Coast 2018.
• It was an international multi-sport event for members of the Commonwealth that were held on the Gold Coast, Australia, between 4 and 15 April 2018.

Additional Information

• The Commonwealth Games often referred to as the Friendly Games, are a quadrennial international multi-sport event among athletes from the Commonwealth of Nations.
• The event was first held in 1930, and, with the exception of 1942 and 1946, has successively run every four years since.

The correct answer is Ashafaqulla Khan

Key Points

• Kakori Conspiracy, also called Kakori Conspiracy Case or Kakori Train Robbery, armed robbery on August 9, 1925, of a train in what is now central Uttar Pradesh state, north-central India, and the subsequent court trial instituted by the government of British India against more than two dozen men accused of involvement.
• Revolutionaries involved in the Kakori Conspiracy Case were hanged.

Additional Information 

• On 19 December 1927, revolutionary freedom fighters Ram Prasad 'Bismil', Ashfaqulla Khan and Thakur Roshan Singh were hanged to death by the British government for their involvement in the Kakori train robbery case.

Shortcut Trick

Rise in water level = (Total Volume Displaced) ÷ (Area of Pool Base)

Total displacement = 150 men × 8 m³ = 1200 m³

Area of pool = 90 m × 40 m = 3600 m²

Rise (h) = 1200 ÷ 3600 = 1/3 m

Rise in cm = (1/3) × 100 = 33.33 cm

∴ The correct answer is 33.33 cm.

Alternate Method

Given:

Dimensions of swimming pool = 90 m × 40 m

Number of men = 150

Average displacement per man = 8 m³

Formula Used:

Volume of water rose = Total volume displaced by men

Area of base × Rise in height (h) = Number of men × Volume displaced per man

Calculations:

⇒ Total volume of water displaced = 150 × 8 = 1200 m³

⇒ Surface area of the pool = 90 × 40 = 3600 m²

⇒ Let h be the rise in water level in meters.

⇒ 3600 × h = 1200

⇒ h = 1200 ÷ 3600

⇒ h = 1/3 m

⇒ To convert meters into centimeters, multiply by 100:

⇒ h = (1/3) × 100 cm

⇒ h ≈ 33.33 cm

∴ The correct answer is 33.33 cm.

Additional Information

Archimedes' Principle

The volume of water displaced by a submerged or floating object is exactly equal to the volume of the object itself.

Volume of a Cuboid

The volume of a cuboidal pool is calculated as V = Length × Width × Depth (or height).

Rise in Level Formula

Rise in Level = (Volume Added) ÷ (Area of the Base). This assumes the base area remains constant throughout the rise.

Unit Conversion Rule

To convert meters to centimeters, multiply by 100; to convert cubic meters to liters, multiply by 1000.

Given:

Traffic Lights change after every 35, 42 & 90 seconds

Initial time = 8:00:00 hours

Concept used:

LCM = Least Common Multiple

It is the product of the greatest power of each prime factor, involved in the numbers.

Solution:

LCM(35, 42, 90) = 2 x 3 x 3 x 5 x 7 = 630

A total of 630 seconds will be required to change the lights simultaneously again.

60 seconds = 1 minute

630 seconds = ? minute

= $\frac{630}{60}$ = 10 minutes 30 seconds.

Hence, 10 minutes and 30 seconds time will be required for them to change again simultaneously.

The correct answer is Buffer solution.

Key Points​​

• A buffer solution is an aqueous mixture of a weak acid and either its conjugate base or base itself. When a modest amount of a strong acid and base is introduced to it, the pH hardly changes at all.
• The two main categories of the buffer are alkaline and acidic buffer solutions. Acidic buffers are solutions that contain a weak acid and one of its salts and have a pH below 7.
• To keep the pH neutral or even slightly alkaline, buffer solutions are employed in the production of many cosmetic and personal hygiene products.

Additional Information​​

• An aqueous solution that has more OH- ions than H+ ions is referred to as a basic solution. It is an aqueous solution with a pH higher than 7, in other words.
• The same concentrations of hydrogen and hydroxide ions are considered to be neutral solutions.
• Higher than that of pure water, an acidic solution has a high concentration of hydrogen ions (H +start superscript). ​

Given:

Old variance = 5

Multiplication factor = m = 2

Formula used:

New variance = m² x Old Variance

Solution:

Let's put the values in the above formula to find the new variant,

New variance = 2² x 5 = 20

Hence, the new variance of the resulting observation is 2² x 5.

The correct answer is Munshi Prem Chand.

Key Points​​​​​​

• Munshi Prem Chand is recognised as one of the greatest Hindi authors of the first half of the twentieth century. He is one of the most well-known authors from the Indian subcontinent,
• Godaan, Karmabhoomi, Gaban, Mansarovar, and Idgah are some of his creations. In a book titled Soz-e-Watan, he initially published his collection of five short stories in 1907.
• Premchand's writings are distinguished by his engaging storytelling and use of straightforward language.

Additional Information​​

• Ramdhari Singh Dinkar was an Indian poet, writer, freedom fighter, patriot, and academic who wrote in Hindi and Maithili. He has been praised as a Rashtrakavi because his poems radiated Veer Rasa.
• One of the most influential Hindi poets of the modern era was Maithili Sharan Gupt. His works of poetry include Jaydrath Vadh and Rang me Bhang.
• Indian poet Sumitra Nandan Pant was born. His best-known works include Pallav and Chidambarab.

The correct answer is Louise Frechette.

Key Points

• On the Security Council's proposal, the General Assembly appoints the Secretary-General.
• Therefore, any of the Security Council's five permanent members may veto the Secretary-appointment. General's
• Canadian diplomat and public servant Louise Frechette held the position of Deputy Secretary-General of the United Nations for eight years.

Additional Information

• From 1997 to 2006, Kofi Annan, a diplomat from Ghana, held the position of seventh Secretary-General of the United Nations.
• Between 2007 to 2016, South Korean politician and diplomat Ban Ki-moon held the position of eighth Secretary-General of the United Nations.
• From April 1953 to September 1961, the second Secretary-General of the United Nations was Dag Hammarskjold, a diplomat, and economist from Sweden.

The correct answer is Denmark.

Key Points​

• Foreign ties between the United Kingdom and Denmark are known as British-Danish relations. Denmark and the United Kingdom each have embassies in the other's capital cities.
• The 1.6 billion euro North Sea Link is referred to as "the world's longest undersea electrical interconnector" by Britain's National Grid.
• The NSL's goal is to utilize both the U.S. and Norway's hydropower.

Additional Information​

• The U.K. and Norway can now share renewable energy thanks to a 450-mile underwater connection that connects the two nations.
• The NSL's goal is to utilise the hydropower in Norway and wind energy in the United Kingdom.
• Hydroelectricity from Norway can be imported when demand is high in Britain but wind generation is low.

Shortcut Trick In the third quadrant, the sine function is always negative. Given cos x = −3/5, we identify the 3-4-5 Pythagorean triplet where base = 3 and hypotenuse = 5. The perpendicular is 4, so the magnitude of sin x is 4/5. Since x is in the third quadrant, sin x must be negative. ∴ The correct answer is −4/5.

Alternate Method Given: cos x = −3/5 and x lies in the third quadrant (180° < x < 270°). Formula Used: sin2x + cos2x = 1

⇒ sin2x = 1 − cos2x ⇒ sin2x = 1 − (−3/5)2 ⇒ sin2x = 1 − 9/25 ⇒ sin2x = 16/25 ⇒ sin x = ± √(16/25) = ± 4/5 Since x lies in the third quadrant, the sine value is negative (sin x < 0). ⇒ sin x = −4/5 ∴ The correct answer is −4/5.

Additional Information ASTC Rule This rule determines the sign of trigonometric ratios: All positive in Q1, Sine in Q2, Tangent in Q3, and Cosine in Q4. Pythagorean Identity For any angle x, the identity sin2x + cos2x = 1 always holds true, derived from the Pythagorean theorem. Trigonometric Ratios In a right-angled triangle, sin θ = Perpendicular/Hypotenuse and cos θ = Base/Hypotenuse.

The correct answer is Pietermaritzburg.

Key Point

• The primary train station for the city of Pietermaritzburg, South Africa, is Pietermaritzburg Railway Station.
• M.K. Gandhi was pulled forcibly from a whites-only carriage on a train to Pietermaritzburg on June 7, 1893, for breaking the law that divided each carriage by race.
• Mahatma Gandhi famously forced off a train at this stop in 1893 because he was traveling first class.

Additional Information

• ​Gandhi was forced out of the train at Pietermaritzburg station despite having a valid first-class ticket and refusing to comply with the instructions. That evening, he had stayed at the station.
• Due to his dusky color, Gandhi was expelled from the train. Gandhi was taken aback. It inspired him to make a shift.
• He spoke with the railroad officials as well, and he got them to agree that Indians who were "fully clothed" might travel in second or first class.

The correct answer is It's main focus is achieving cleanliness only in urban areas of India.

Key Points​​​

• The government of India launched the Swachh Bharat Abhiyan, a nationwide effort, in 2014 to end open defecation and enhance solid waste management.
• The Government of India is conducting a nationwide drive to clean the nation's streets, highways, and infrastructure in 4041 statutory towns.
• Clean India Mission for Cities. The program includes eradicating open defecation, converting unhygienic toilets to pour flush toilets, eliminating manual scavenging, managing municipal solid waste, and changing people's attitudes toward good sanitation practices.

Additional Information

• The Swachh Bharat Mission was established by the Indian Prime Minister on October 2, 2014, to focus on sanitation and to speed up efforts to attain universal sanitation coverage.
• For the fifth year running, Indore has held the title of "Cleanest City" in India without being contested, winning the prized designation at the Swachh Survekshan Award 2021.
• The National Tricolor is used to represent the bridge of Mahatma Gandhi's spectacles in the Swachh Bharat Mission logo.

Given:

Principle = ₹ 5,000

Rate = 4%

Time = 1.5 years

Formula used:

$A= P \times [1 + {R\over 100}]^T$

CI = A - P

here, 

A = Amount

CI = Compound Interest

P = Principle

R = Rate

T = Time

Solution:

Let's put the values given, in the formula to find the value of A;

For Compounded yearly,

1^st year: P = 5000 & R = 4%

$A= P \times [1 + {R\over 100}]^T = 5000 \times [1 + {4\over 100}]^1 = ₹\ 5200$

CI = A - P = 5200 - 500 = ₹ 200

1/2 year: P = ₹ 5200 & R = 4/2 = 2%

$A= P \times [1 + {R\over 100}]^T = 5200 \times [1 + {2\over 100}]^1 = 5304$

CI = A - P = 5304 - 5200 = ₹ 104

Total Interest for compounded annually = 200 + 104 = ₹ 304

For Compounded Half Yearly,

P = ₹ 5000

R = 4/2 = 2%

T = 3

$A= P \times [1 + {R\over 100}]^T = 5000 \times [1 + {2\over 100}]^3 = 5306.04$

CI = 5306.04 - 5000 = ₹ 306.04

Now, the difference be compounded annually and half-yearly = 5306.04 - 5304 = ₹ 2.04

Hence, the difference between the compound interests is ₹ 2.04.

Given:

Perimeter of 5 squares = 24cm, 32 cm, 40cm, 76cm, 80cm.

Area of another square = Sum of areas of the above 5 squares.

Formula used:

Area of square = side x side

Perimeter of square = 4 x side

Solution:

First of all, we will find the side of 5 squares then, we will find their area, sum up them, and find the side of another square, to calculate its perimeter.

Side of 1^st square = 24/4 = 6 cm

Side of 2^nd square = 32/4 = 8 cm

Side of 3^rd square = 40/4 = 10 cm

Side of 4rth square = 76/4 = 19 cm

Side of 5^th square = 80/4 = 20 cm

now, 

Area of 1^st square = 6 x 6 = 36 cm²

Area of 2^nd  square = 8 x 8 = 64 cm2

Area of 3^rd square = 10 x 10 = 100 cm2

Area of 4rth square = 19 x 19 = 361 cm2

Area of 5^th square = 20 x 20 = 400 cm²

Now, Area of another square = 36 + 64 + 100 + 361 + 400 = 961 cm²

Hence, the side of another square = 31 cm

Perimeter of another square = 4 x 31 = 124 cm.

The table showing the positional value of the alphabets is given below.

Here, the following logic is used,

Therefore, '?' will be replaced by 'P'.

Hence, the correct answer is option 3).

Given:

Total number of students in a school = 2401

Explanation:

Here, the number of rows and number of columns are equal and the total number of students is 2401.

To find the number of rows and columns will take the square root of the total number of students

Therefore, $\sqrt{2401}$ = 49

Hence, the number of rows or columns is 49.

Here, all figures are identical, except figure(3).

In Figure(3) an arrow has a diagonal line in it whereas other figures have a plain arrow.

Hence, the correct answer is option 3).

Given:

Principle = ₹ 5000

Rate = 12%

Time = 5 years

Formula used:

SI = ${P \times R \times T \over 100}$

A = SI  + P

here, 

A = Amount

SI= Simple Interest

P = Principle

R = Rate

T = Time

Calculation:

Let's put the values given, in the formula to find the value of SI;

SI =  ${P \times R \times T \over 100}= {5000 \times 12 \times 5 \over 100}$

SI = ₹ 3000

Now, A = SI + P = 3000 + 5000 = ₹ 8000

Hence, the amount after 5 years will be ₹ 8000.

Given:

Principle = ₹ 1000

Rate = 10%

Amount = ₹ 1,331

Formula used:

$A= P \times [1 + {R\over 100}]^T\$

A = CI + P

here, 

A = Amount

CI = Compound Interest

P = Principle

R = Rate

T = Time

Calculation:

Let's put the values given, in the formula to find the value of T;

$A= P \times [1 + {R\over 100}]^T \ 1331 = 1000[1+{10\over 100}]^T \ 1331 = 1000[1.1]^T \ 1.331 = [1.1]^T \ [1.1]^3 = [1.1]^T \ T = 3$

Hence, the value of time is 3 years.

The correct answer is Microsoft Office.

Key Points

• An operating system is a piece of system software that controls computer resources, hardware, and common services for software programs.
• An operating system is a program that controls all other application programs in a computer after being loaded into the system first by a boot program.
• Microsoft Office is a collection of programs made to increase productivity and carry out typical operations on a computer.

Additional Information​

• These are some applications for using Linux: Server OS for shared servers of any kind, including web servers, database servers, file servers, email servers, etc.
• Microsoft Windows is a personal computer operating system (OS) created by the Microsoft Corporation. It is also known as Windows and Windows OS (PCs).
• Apple's desktop OS now has a lot of new features and improvements thanks to macOS Mojave. Stacks aid in maintaining a neat desktop. A system-wide dark mode is visually appealing and helps with evening computer use.

The Persian language is also known as 'Farsi' and is spoken in Iran.

Similarly,

English is a language spoken in 'South Africa'.

Hence, the correct answer is an option(2)

The correct answer is Black rust in wheat.

Key Points

• The fungus Puccinia graminis tritici causes the black rust of wheat.
• The disease is also known as stem rust of wheat.
• It affects the grains, stems, and leaves of the plant.
• **Heteroecious Puccinia graminis tritici.
• The parasite needs two partners in order to complicate its life because it belongs to the heteroecious family.
• Wheat and Kentucky blue grass stem rust are caused by Puccinia garminis.

Additional Information

• Red rot, prevalent in South Asia and Indonesia, is distinguished by sporadic red and white patches inside the cane and a sour alcoholic odor when the rod is split open.
• Late blight, is the most significant potato disease, which is brought on by the fungus Phytophthora infestans and can quickly lead to crop failures if proper control measures are not taken.
• A ring-shaped rash that is itchy, scaly, and slightly elevated is frequently caused by ringworm. Typically, the rings begin small and then spread outward. A rash known as ringworm of the body (tinea corporis) is brought on by a fungus. The rash is typically round and irritating, with clearer skin in the center.

The correct answer is Maharashtra.

Key Points

• Paithan Hydroelectric Project is located in Maharastra.
• It was made at the Godavari river.
• It is completed with the help of Japan.
• The dam's created reservoir is known as Nath Sagar Jalashay.
• Mrs. Indira Gandhi, the prime minister at the time, gave it its inauguration in 1976.

Additional Information

• Dams in Rajasthan:
• Jawai Dam
• Mahi DAm]
• Bisalpur dam
• Jawar Sagar Dam, etc.
• Dams in Uttar Pradesh:
• Adwa Dam
• Afzalgarh Dam
• Ahraura Dam
• Arjun Dam, etc.
• Dams in West Bengal
• Bakreshwar Dam Siuri
• Bandhu Dam Puruliya
• Bara Mandira Dam Asansol
• Barabhum Dam:

The correct answer is 5%, 12%, 18% and 28%.

Key Points

• GST tax slab of 5%
• Goods – Spices, chapati, edible oil, bread, pizza bread, fish, Khakhra, tea and coffee, etc.

Services – aircraft lease, crude and petroleum transport, takeaway food, economy flight tickets, etc.

• GST tax slab of 6%
• Goods –  Frozen meat, meat sausages, juices, sauces, cakes, pickles, boiled sugar, products made of milk, etc.

Services – Business class flight tickets, movie tickets, hotel stay (Price < INR 7,500), eating and drinking outlet.

• GST tax slab of 18%
• Goods –  Mineral water, raw pasta, biscuits, pastries, soup, cornflakes, curry powder and paste, etc.

Services – Movie tickets (> INR 100), Hotel accommodation (>= INR 7,500), Daily room (from INR 2,500 and 5,000), etc.

• GST tax slab of 28%
• Goods – Aerated water (with or without added sugar), instant coffee, chocolates, protein, coffee and custard concentrates, etc.

Services – Hotel stay wherein bill is > INR 7,500, gambling, go-karting, ballet, club services such as casinos, etc.

Additional Information

• GST has been structured in a way that essential services and food items are placed in the lower tax brackets.
• Luxury services and products have been placed in the higher tax bracket.
• The GST council has fitted over 1300 goods and 500 services under four tax slabs of 5%, 12%, 18% and 28%.
• A total of 81% of all the goods and services fall below or in the 18% tax slab.
• 7% of the items come under the exempted list, 14% of the items attract a 5% tax and 17% of the items attract a 12% tax.
• 43% of the items attract an 18% tax slab, while only 19% of the items fall under the highest slab of 28% in the new regime.

The correct answer is Water vapour, CO2 and CFCs.

Key Points

Examples of Greenhouse Gases:

• Water Vapour (H₂O) – The most abundant natural greenhouse gas.
• Carbon Dioxide (CO₂) – Released from fossil fuel burning and deforestation.
• Methane (CH₄) – Emitted from livestock, agriculture, and landfills.
• Nitrous Oxide (N₂O) – Comes from fertilizers, burning fossil fuels, and biomass.
• Ozone (O₃) – Found in the lower atmosphere (troposphere) and contributes to warming.
• Chlorofluorocarbons (CFCs) & Fluorinated Gases – Synthetic gases used in refrigeration and industrial processes.

Additional Information

• Greenhouse effect
• Without the greenhouse effect, Earth's average temperature would drop from ~14°C to as low as –18°C, making it too cold for life.
• Greenhouse gas emissions increased by approximately 70% between 1970 and 2004 due to industrial activities, deforestation, and fossil fuel use.
• CO₂ emissions rose by about 80% during that period, largely due to human activities such as burning coal, oil, and gas.
• As the levels of greenhouse gases increase, Earth's temperature rises, leading to climate changes.
• The rise in Earth's average temperature due to human activity is known as global warming.

Given series: 

6 : 34 :: 8 : 62 :: 9 : ?

Here, the following logic is used 

(First number)² - 2 = Second number

First pair

**(**6)² - 2 = 6 × 6 - 2

= 36 - 2

= 34

Second Pair (8)² - 2 = 8 × 8 - 2

= 64 - 2

= 62

Third Pair 

(9)² - 2 = 9 × 9 - 2

= 81 - 2

= 79

Therefore, '?' will be replaced by '79'

Hence, the correct answer is option 4).

Given Statements:

Nurses marry only tall men.

Ankit is very tall.

Conclusions:

I. Ankit was married to a nurse.

II. Ankit was not married to a nurse.

Conclusion 1: Since all the nurses marry only the tall men and Ankit is very tall, this conclusion may follow.

Conclusion 2: Ankit is very tall, but it is not explicitly mentioned that he marries a nurse, so there is a possibility that he did not married to a nurse.

Hence, this conclusion may also follow.

From the above, it is clear that either conclusion I or conclusion II follows.

Hence, the correct answer is option 1).

The correct answer is ​Common Business-Oriented Language.

Key Points

• COBOL
• COBOL stands for Common Business-Oriented Language.
• It is a 60-year-old programming language that is still widely used today.
• It was developed in 1959 by CODASYL (Conference/Committee on Data Systems Languages).
• It is an English-like computer programming language used for business.
• The syntax was developed to be simple and explicit.
• The non-programmers in business environments could understand it without needing extensive knowledge of coding.

Additional Information

• COBOL has strict rules regarding syntax and organization.
• The code for a program written in COBOL is broken up into divisions.
• It make it easy to locate and understand the individual components.
• Each program consists of four divisions:
• Identification division
• Environment division
• Data division
• Procedure division

The correct answer is Beta test.

Key Points

• Beta test
• A beta test is a type of trial period for a computer product prior to a commercial or official release.
• Beta testing is considered the last stage of testing before launch.
• It normally involves the distribution of the product to external beta test sites and individual users for real-world exposure.
• Other beta tests may offer the product for a free trial download over the Internet.

Additional Information

• Alpha test
• Alpha testing is the first end-to-end testing of a product to ensure it meets the business requirements and functions correctly.
• It is typically performed by internal employees and conducted in a lab/stage environment.
• An alpha test ensures the product really works and does everything it's supposed to do.
• Delta test
• Delta testing is automated user testing.
• It's a proven, cost-effective approach to legacy user testing that allows companies to capture early product feedback from customers.
• This gives companies the customer insights they need to develop high-quality products their customers will love.

The correct answer is Canada.

Key Points

• Canada occupies most of the northern part of North America.
• The country occupies an area of 9,984,670 km², making it the largest country in the Western Hemisphere.
• Compared, it is slightly larger than the US, or 18 times the size of France.
• It has 13 sub-national divisions, ten provinces and three territories.
• Canada is divided into multiple geographical regions, and its landscape offers a wide range of natural sceneries.

Additional Information

The top ten largest countries, in square kilometers

The correct answer is Article 23.

Key Points

• Article 23
• ​The right against Exploitation is enshrined in Articles 23 and 24 of the Indian Constitution.
• Traffic in human beings and beggars and other similar forms of forced labor are prohibited.
• Any contravention of this provision shall be an offense punishable in accordance with the law.
• Article 23 protects citizens not only against the State but also from private citizens.
• Laws passed by the Parliament in pursuance of Article 23:
• Suppression of Immoral Traffic in Women and Girls Act, 1956
• Bonded Labour System (Abolition) Act, 1976

Additional Information

• Article 19
• Protection of certain rights regarding freedom of speech etc.
• All citizens shall have the right
• to freedom of speech and expression
• to assemble peaceably and without arms
• to form associations or unions
• to move freely throughout the territory of India
• to reside and settle in any part of the territory of India
• Article 21
• The Right to Life and Personal Liberty is assured by the Indian Constitution under Article 21.
• No person shall be deprived of his life or personal liberty except according to procedure established by law.
• This fundamental right is available to every person, citizens and foreigners alike.
• Article 21 provides two rights:
• Right to life
• Right to personal liberty
• Article 14
• Article 14 treats all people the same in the eyes of the law.
• This provision states that all citizens will be treated equally before the law.
• The law of the country protects everybody equally.
• Under the same circumstances, the law will treat people in the same manner.

Given:

Speed from village to Post Office = S₁ = 25 km/h

Speed from Post-office to village = S₂ = 4 km/h

Total time = 5 hours 48 minutes = 5.8 hours

Formula used:

Time = $\frac{Distance}{Speed}$

Calculation:

Let's put the values in the above formula,

Time = $\frac{Distance}{Speed}$

T₁ = $\frac{d}{25}$

T₂ = $\frac{d}{4}$

⇒ T1 + T2 = ${d \over 25} + {d \over 4}$

⇒ 5.8 = ${4d + 25d \over 100}$

⇒ 580 = 29d

⇒ d = 20

Hence, the distance is 20 km.

Given:

Speed of A = 60 km/h

Speed of B = 75 km/h

Speed of C = 80 km/h

T(A) = T(B) + 5

T(A) = T(C) + h

Formula used:

Distance = Speed x Time

Solution:

Let, t = time taken by B

The distance traveled is the same for A & B thus,

60 x (t + 5) = 75 x t

60t + 300 = 75t

15t = 300

t = 20

Distance traveled by B = 75 x 20 = 1500 km

Now,

For B & C, the distance is the same,

T(C) x 80 = 1500

T(C) = $\frac{75}{4}$ hours = 18 hours 45 minutes

Now, the Time taken by A = T(A) = t + 5 = 20 + 5 = 25 hours

So, h = difference between the time of A & C

T(A) = T(C) + h

h = T(A) - T(C) = 25 hours - 18 hours 45 minutes = 6 hours 15 minutes.

Hence, C started after 6 hours and 15 minutes.

The correct answer is Section 144.

Key Points

• Section 144
• Section 144 is imposed in urgent cases of nuisance or apprehended danger of some event that has the potential to cause trouble.
• Section 144 of CrPC generally prohibits public gatherings.
• It has been used in the past to impose restrictions as a means to prevent protests that can lead to unrest or riots.
• The orders to impose Section 144 have been conferred to the Executive Magistrate when there is an emergency situation.
• Section 144 also restricts carrying any sort of weapon in that area where it has been imposed.
• The maximum punishment for such an act is three years.

Additional Information

• Section 231
• Whoever counterfeits or knowingly performs any part of the process of counterfeiting coins, shall be punished with imprisonment.
• The punishment would be of:
• either description for a term which may extend to seven years
• shall also be liable to fine.
• Section 111
• When an Act is abetted and a different act is done, the abettor is liable for the act don.
• It is in the same manner and to the same extent as if he had directly abetted it.
• Section 357
• Whoever assaults or uses criminal force to any person he/she shall be pun­ished with imprisonment of either description.
• It is for a term which may extend to one year, or with fine which may extend to one thousand rupees, or with both.

The correct answer is Tripura.

Key Points

• Five Indian states Uttarpradesh, Uttarakhand, West Bengal, Sikkim and Bihar share their borders with Nepal.
• Tripura does not share any border with Nepal.
• Tripura is surrounded by Bangladesh on its north, south and west.
• The length of its international border is 856 km.
• The state is connected with the rest of India by NH-44 which runs through Assam, Meghalaya, North Bengal, Kolkata and other parts of India.

Additional Information

Given:

${ {144 \over 0.144} = { 14.4 \over x}}$

Calculation:

${ {144 \over 0.144} = { 14.4 \over x}} \ { {144 \over 0.144} \times { 1000\over1000} } = { {14.4 \over x} \times {10\over 10}}\ { {144000 \over 144}} = { {144 \over 10x}}\ { 1000} = { {144 \over 10x}}\$

The value of x = $\frac{144}{10000}$ = 0.0144

The correct answer is 4D.

Key Points

• Given focal length = 25 cm
• Power of lens = $100/f$
• Power of lens = 100/25 = 4D

Additional Information

• Power of lens
• The inverse of the focal length is known as the power of the lens.
• The unit of power of the lens is Dioptre.
• P =1/f where P is the lens whose refracting surface e power of the lens and f is the focal length.
• Concave lens
• It is a diverging lens that diverges the parallel beam of light.
• The focal length of the concave lens is negative.
• Convex length
• The lens whose refracting surface is upside is called a convex lens.
• The focal length of a convex length is positive.

Statement Given:

A signboard in a park states: Please use the dustbin, do not litter, and help keep your community clean.

Assumptions Given:

I. Throwing litter around makes a community dirty.

II. People are likely to pay attention to this notice.

Assumption I,

As it is given to use the dustbin and not to litter there and here, which means throwing litter makes a community dirty. This is implicit above.

Assumption II,

Since the signboard is placed in the park, it is clear that people are likely to pay attention to this notice. So, this assumption is also implicit here.

Therefore, both I and II are implicit.

Hence, the correct answer is an option(3)