Previous Year Paper

RRB Technician Grade III Official Paper (Held On: 27 Dec, 2024 Shift 3) (Previous Year Paper)

Held in 2024

100 questions90 minutes
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Full Test (100 questions)

Question 1

Which products are formed in the chlor-alkali process when electricity is passed through an aqueous sodium chloride solution?

NaCl(aq) + H2O(I) → Products

  1. AOption (a)

    NaCl + H2

  2. BOption (b)

    NaHCO3 + Cl2

  3. COption (c)

    H2 + O2

  4. DOption (d)

    NaOH + H2 + Cl2

View answer & explanation

Correct answer

Answer: (d)D.

NaOH + H2 + Cl2

Why this answer is correct

The correct answer is NaOH + H2 + Cl2.

Key Points

  • The chlor-alkali process involves the electrolysis of an aqueous sodium chloride (NaCl) solution, also known as brine.
  • When electricity is passed through the brine, it decomposes into three main products: sodium hydroxide (NaOH), chlorine gas (Cl2), and hydrogen gas (H2).
  • The reactions occurring at the electrodes are:
  • Cathode (Reduction): 2H2O + 2e- → H2 + 2OH-
  • Anode (Oxidation): 2Cl- → Cl2 + 2e-
  • The sodium ions (Na+) in the solution combine with the hydroxide ions (OH-) to form sodium hydroxide (NaOH).
  • The products NaOH, H2, and Cl2 are commercially valuable. Sodium hydroxide is used in the manufacture of paper, soap, and detergents. Chlorine is used for disinfecting water, in the production of PVC, and in the manufacture of various chemicals. Hydrogen is used in hydrogenation processes and as a fuel.

 Additional Information

  • NaCl + H2
  • This option is incorrect because sodium chloride (NaCl) is the reactant, not the product, in the chlor-alkali process.
  • Hydrogen gas (H2) is indeed produced, but not sodium chloride.
  • NaHCO3 + Cl2
  • This option is incorrect because sodium bicarbonate (NaHCO3) is not produced in the chlor-alkali process.
  • Chlorine gas (Cl2) is produced, but not sodium bicarbonate.
  • H2 + O2
  • This option is incorrect because oxygen gas (O2) is not produced in the chlor-alkali process.
  • Hydrogen gas (H2) is produced, but not oxygen.

Question 2

A series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called _______.

  1. AOption (a)

    homologous series 

  2. BOption (b)

    isomers 

  3. COption (c)

    isochores 

  4. DOption (d)

    isobars 

View answer & explanation

Correct answer

Answer: (a)A.

homologous series 

Why this answer is correct

The correct answer is homologous series.

Key Points

  • A homologous series is a group of organic compounds that have a similar general formula and possess similar chemical properties.
  • In a homologous series, each successive member differs by a -CH2- unit.
  • The members of a homologous series are called homologues.
  • Homologous series exhibit a gradual change in physical properties such as boiling point, melting point, and density.
  • Examples of homologous series include alkanes, alkenes, and alkynes.
  • One notable characteristic is that the functional group remains the same throughout the series.
  • Homologous series are important in organic chemistry because they help in the systematic study and prediction of properties of organic compounds.

 Additional Information

  • Isomers
  • Isomers are compounds that have the same molecular formula but different structural arrangements.
  • Isomers can be classified into structural isomers and stereoisomers.
  • Structural isomers have different connectivity of atoms, while stereoisomers have the same connectivity but differ in spatial arrangement.
  • Isochores
  • Isochores are regions of DNA with a high degree of uniformity in base composition.
  • They are significant in the field of genetics and genomics.
  • Isobars
  • Isobars are atoms of different chemical elements that have the same number of nucleons.
  • Isobars differ in chemical properties because they have different atomic numbers.

Question 3

Find the compound interest on Rs. 13,000 in 2 years at 4% p.a., interest compounded yearly.

  1. AOption (a)

    Rs. 996.50

  2. BOption (b)

    Rs. 1086.60

  3. COption (c)

    Rs. 997.60

  4. DOption (d)

    Rs. 1060.80

View answer & explanation

Correct answer

Answer: (d)D.

Rs. 1060.80

Why this answer is correct

Shortcut Trick

Effective Rate of Interest for 2 years at 4% = x + y + (xy/100)

⇒ 4 + 4 + (4 × 4)/100 = 8.16%

Compound Interest = 8.16% of ₹13,000

⇒ 130 × 8.16 = ₹1060.80

∴ The correct answer is ₹1060.80.

Alternate Method

Given: Principal (P) = ₹13,000, Rate (R) = 4%, Time (n) = 2 years

Formula Used: Amount (A) = P(1 + R/100)n; CI = A − P

⇒ A = 13000(1 + 4/100)2

⇒ A = 13000(104/100) × (104/100)

⇒ A = 130 × 1.04 × 104 = 14060.80

⇒ CI = 14060.80 − 13000

⇒ CI = ₹1060.80

∴ The correct answer is ₹1060.80.

Additional Information

Successive Percentage Method

Compound interest is essentially the result of successive percentage increases on the principal amount.

Difference between SI and CI

For 2 years, the difference between CI and SI is given by the formula: D = P(R/100)2.

Compounding Half-Yearly

If interest is compounded half-yearly, the rate is halved (R/2) and the time is doubled (2n).

Question 4

The average temperature for Monday, Tuesday, Wednesday, and Thursday was 48ºC, and for Tuesday, Wednesday, Thursday, and Friday was 46ºC. If the temperature on Monday was 42ºC, find the temperature on Friday.

  1. AOption (a)

    40ºC

  2. BOption (b)

    36ºC

  3. COption (c)

    38ºC

  4. DOption (d)

    34ºC

View answer & explanation

Correct answer

Answer: (d)D.

34ºC

Why this answer is correct

Shortcut Trick

Net difference between Monday and Friday = Number of days × (Difference in averages)

⇒ Monday − Friday = 4 × (48 − 46) = 4 × 2 = 8°C

⇒ 42 − Friday = 8

⇒ Friday = 42 − 8 = 34°C

∴ The correct answer is 34°C.

Alternate Method

Given:

Average (Mon, Tue, Wed, Thu) = 48°C

Average (Tue, Wed, Thu, Fri) = 46°C

Temperature on Monday = 42°C

Formula Used:

Sum of observations = Average × Number of observations

Calculations:

⇒ Sum(Mon + Tue + Wed + Thu) = 48 × 4 = 192°C

⇒ Sum(Tue + Wed + Thu + Fri) = 46 × 4 = 184°C

⇒ (Mon + Tue + Wed + Thu) − (Tue + Wed + Thu + Fri) = 192 − 184

⇒ Mon − Fri = 8°C

⇒ 42 − Fri = 8

⇒ Fri = 42 − 8 = 34°C

∴ The correct answer is 34°C.

Additional Information

Average of a Group

Average = (Sum of all observations) ÷ (Total number of observations).

Deviation Method

If one member is replaced, the change in sum = (Number of members) × (Change in Average).

Temperature Problems

In overlapping day series, common days cancel out when subtracting the total sums of the two sets.

Question 5

Which statement is NOT true for magnetic field lines? 

  1. AOption (a)

    Magnetic field lines are not closed curves. 

  2. BOption (b)

    No two field lines are found to cross each other. 

  3. COption (c)

    Inside the magnet, the direction of field lines is from its south pole to its north pole.

  4. DOption (d)

    The relative strength of the magnetic field is shown by the degree of closeness of the field lines. 

View answer & explanation

Correct answer

Answer: (a)A.

Magnetic field lines are not closed curves. 

Why this answer is correct

The correct answer is Magnetic field lines are not closed curves..

Key Points

  • Magnetic field lines are indeed closed curves. They start from the north pole of a magnet and end at the south pole, forming continuous loops inside and outside the magnet.
  • No two field lines are found to cross each other. If they did, it would mean that the magnetic field has two directions at that point, which is not possible.
  • Inside the magnet, the direction of field lines is from its south pole to its north pole. This is part of the continuous loop of the magnetic field lines.
  • The relative strength of the magnetic field is shown by the degree of closeness of the field lines. The closer the lines, the stronger the magnetic field in that region.

 Additional Information

  • No two field lines cross each other
  • If two magnetic field lines crossed, it would imply that the magnetic field has two different directions at the same point, which is impossible.
  • Inside the magnet, the direction of field lines is from south to north
  • This indicates that magnetic field lines form closed loops, going from north to south outside the magnet and from south to north inside the magnet.
  • The relative strength of the magnetic field
  • The closeness of magnetic field lines indicates the strength of the magnetic field; closer lines mean a stronger field.

Question 6

In an election between two candidates, one got 55% of the total valid votes, and 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got was:

  1. AOption (a)

    3000

  2. BOption (b)

    2700

  3. COption (c)

    2600

  4. DOption (d)

    3300

View answer & explanation

Correct answer

Answer: (b)B.

2700

Why this answer is correct

Shortcut Trick

Total Votes = 7500

Valid Votes = 80% of 7500 = 6000

Winner gets 55%, so Other Candidate gets 45% of valid votes.

Other Candidate = 45% of 6000 = 0.45 × 6000 = 2700

∴ The correct answer is 2700 votes.

Alternate Method

Given:

Total votes = 7500

Invalid votes = 20%

Winner candidate share = 55% of valid votes

Calculations:

⇒ Total Valid votes = 7500 × (100 − 20)%

⇒ Total Valid votes = 7500 × 80/100 = 6000

⇒ Other candidate share = 100% − 55% = 45% of valid votes

⇒ Votes for other candidate = 45/100 × 6000

⇒ Votes for other candidate = 45 × 60 = 2700

∴ The correct answer is 2700 votes.

Additional Information

Percentage Base Change

Always identify the correct base for percentages. In elections, candidate percentages are usually calculated on Valid Votes, not Total Votes, unless specified otherwise.

Successive Percentage Shortcut

Result = Total × (Valid % / 100) × (Candidate % / 100). Here, 7500 × 0.80 × 0.45 = 2700.

Question 7

The population of a town is 1,76,400. If it increases at the rate of 5% per annum, then what will be its population 2 years hence?

  1. AOption (a)

    1,94,481

  2. BOption (b)

    1.94,621

  3. COption (c)

    1,94,572

  4. DOption (d)

    1,93,636

View answer & explanation

Correct answer

Answer: (a)A.

1,94,481

Why this answer is correct

Shortcut Trick

Growth rate = 5% → Multiplying factor = 1 + 5/100 = 1.05

Successive increase for 2 years = (1.05)2 = 1.1025

New Population = 1,76,400 × 1.1025 = 1,94,481

∴ The correct answer is 1,94,481.

Alternate Method

Given:

Present Population (P) = 1,76,400

Rate of Increase (R) = 5%

Time period (n) = 2 years

Formula Used:

Population after n years = P × (1 + R/100)n

Calculations:

⇒ Population = 1,76,400 × (1 + 5/100)2

⇒ Population = 1,76,400 × (105/100) × (105/100)

⇒ Population = 1,76,400 × (21/20) × (21/20)

⇒ Population = 1,76,400 × (441/400)

⇒ Population = 441 × 441

⇒ Population = 1,94,481

∴ The correct answer is 1,94,481.

Additional Information

Population Decrease

If the population decreases at rate R, the formula becomes: P × (1 − R/100)n.

Successive Percentage Method

For two years, the net percentage change can be calculated as x + y + (xy/100). Here, 5 + 5 + (25/100) = 10.25%.

Finding Previous Population

To find the population n years ago, the formula is: Population / (1 + R/100)n.

Question 8

Evaluate the given expression. (24 ÷ 3) × 2

  1. AOption (a)

    12

  2. BOption (b)

    4

  3. COption (c)

    16

  4. DOption (d)

    18

View answer & explanation

Correct answer

Answer: (c)C.

16

Why this answer is correct

Given:

(24 ÷ 3) × 2

Formula used:

BODMAS rule (Bracket, Of, Division, Multiplication, Addition, Subtraction)

Calculations:

(24 ÷ 3) × 2

⇒ 8 × 2

⇒ 16

∴ The correct answer is option (3).

Question 9

By selling 8 oranges for ₹40, a man loses 20%. How many should he sell for ₹30 to gain 20% in the transaction?

  1. AOption (a)

    3

  2. BOption (b)

    4

  3. COption (c)

    2

  4. DOption (d)

    5

View answer & explanation

Correct answer

Answer: (b)B.

4

Why this answer is correct

Shortcut Trick

Using the price-quantity-percentage relation: (Price1) ÷ (Quantity1 × Selling%1) = (Price2) ÷ (Quantity2 × Selling%2)

Here, Selling%1 = 100% − Loss% = 100% − 20% = 80%

And, Selling%2 = 100% + Gain% = 100% + 20% = 120%

Let the required quantity of oranges be x.

⇒ 40 ÷ (8 × 80) = 30 ÷ (x × 120)

⇒ 40 ÷ 640 = 30 ÷ (120x) ⇒ 1 ÷ 16 = 1 ÷ (4x) ⇒ 4x = 16 ⇒ x = 4

∴ The correct answer is 4.

Alternate Method

Given:

Selling Price (SP1) of 8 oranges = ₹40

Loss percentage = 20%

Desired Gain percentage = 20%

New Total Selling Price (SP2) = ₹30

Formulas:

Cost Price (CP) = SP × 100 ÷ (100 − Loss%)

New Selling Price (SP) = CP × (100 + Gain%) ÷ 100

Steps:

⇒ SP of 1 orange in first case = 40 ÷ 8 = ₹5

⇒ Since there is a 20% loss, CP of 1 orange = 5 × 100 ÷ (100 − 20) = 5 × 100 ÷ 80 = ₹6.25

⇒ CP of 8 oranges = 8 × 6.25 = ₹50

⇒ To gain 20%, SP of 8 oranges should be = 50 × (100 + 20) ÷ 100 = 50 × 1.2 = ₹60

⇒ If 8 oranges are sold for ₹60 to get 20% gain, then the number of oranges to be sold for ₹30 is:

⇒ Quantity for ₹30 = (8 ÷ 60) × 30 = 4 oranges

∴ The correct answer is 4.

Additional Information

Unitary Method in Price and Quantity

For a constant total value, the quantity sold is inversely proportional to the price per unit. When the required profit increases, the selling price per unit increases, which means fewer items must be sold for the same amount of money.

Question 10

The work done by a constant force acting on a body is ______

  1. AOption (a)

    either positive or negative  

  2. BOption (b)

    always zero 

  3. COption (c)

    always positive  

  4. DOption (d)

    always negative  

View answer & explanation

Correct answer

Answer: (a)A.

either positive or negative  

Why this answer is correct

The correct answer is either positive or negative.

Key Points

  • The work done by a constant force on a body depends on the direction of the force relative to the direction of the displacement of the body.
  • If the force is in the same direction as the displacement, the work done is positive.
  • If the force is in the opposite direction to the displacement, the work done is negative.
  • When the force and displacement are perpendicular to each other, the work done is zero.
  • Therefore, the work done by a constant force can be positive, negative, or zero.

 Additional Information

  • always zero
  • This option is incorrect because the work done by a constant force is not always zero.
  • Work done can be zero only if the force is perpendicular to the displacement.
  • always positive
  • This option is incorrect because the work done by a constant force is not always positive.
  • Work done is positive only if the force is in the same direction as the displacement.
  • always negative
  • This option is incorrect because the work done by a constant force is not always negative.
  • Work done is negative only if the force is in the opposite direction to the displacement.

Question 11

Who took over as the new Director General (Acquisition) in the Defence Ministry in January 2024?

  1. AOption (a)

    Arun Kumar Sinha

  2. BOption (b)

    Ramesh Chandra

  3. COption (c)

    Samir Kumar Sinha

  4. DOption (d)

    Rajeev Kumar

View answer & explanation

Correct answer

Answer: (c)C.

Samir Kumar Sinha

Why this answer is correct

The correct answer is Samir Kumar Sinha.

Key Points

  • Samir Kumar Sinha took over as the new Director General (Acquisition) in the Defence Ministry in January 2024.
  • The position of Director General (Acquisition) plays a crucial role in overseeing and managing the procurement of defense equipment and services for the Indian Armed Forces.
  • Prior to this appointment, Samir Kumar Sinha has held various significant positions within the defense sector.
  • The role is vital for ensuring that the defense acquisition process is streamlined, transparent, and efficient.
  • The appointment comes at a time when the Indian government is focusing on modernizing its defense forces and enhancing self-reliance in defense production.

Question 12

The kind of energy possessed by a moving body by virtue of its motion is _______

  1. AOption (a)

    electromagnetic energy 

  2. BOption (b)

    nuclear energy  

  3. COption (c)

    kinetic energy  

  4. DOption (d)

    potential energy 

View answer & explanation

Correct answer

Answer: (c)C.

kinetic energy  

Why this answer is correct

The Correct answer is kinetic energy.

Key Points

  • Kinetic energy is the energy possessed by a body due to its motion.
  • It is calculated using the formula: KE = 1/2 mv², where m is the mass of the object and v is its velocity.
  • All moving objects have kinetic energy, regardless of their direction of motion.
  • Examples include a moving car, a flying airplane, a flowing river, and even the particles in a gas or liquid.
  • Conversion of energy: Kinetic energy can be converted into other forms of energy, such as potential energy, thermal energy, etc.
  • It is a scalar quantity and always has a positive value.
  • The SI unit of kinetic energy is the joule (J).

 Additional Information

  • Electromagnetic energy
  • Electromagnetic energy is a form of energy that is reflected or emitted in the form of electrical and magnetic waves that can travel through space.
  • Examples include light, radio waves, and X-rays.
  • Nuclear energy
  • Nuclear energy is the energy released during nuclear reactions, such as fission or fusion.
  • It is used in nuclear power plants and nuclear weapons.
  • Potential energy
  • Potential energy is the energy possessed by an object due to its position or configuration.
  • Examples include a stretched spring or an object held at a height.

Question 13

Town I is to the east of Town X. Town L is to the west of Town X. Town N is to the north of Town L. Town P is to the north-east of Town L. Town P is to the east of Town N. Town I is to the south-west of Town P. What is the position of Town P with respect to Town X?

  1. AOption (a)

    North-east

  2. BOption (b)

    West

  3. COption (c)

    South-west

  4. DOption (d)

    East

View answer & explanation

Correct answer

Answer: (a)A.

North-east

Why this answer is correct

Given: 

Town I is to the east of Town X.

Town L is to the west of Town X.

Town N is to the north of Town L.

Town P is to the north-east of Town L.

Town P is to the east of Town N.

Town I is to the south-west of Town P. 

So, Town P is in 'North-east' direction with respect to Town X

Hence, the correct answer is "Option 1".

Question 14

Select the term which is not an identity.

  1. AOption (a)

    (a + b)2 = a2 + b2 + 2ab

  2. BOption (b)

    (a + 1)(a + 2) = a2 + 3a + 2

  3. COption (c)

    (a + b)2 = a2 + b2

  4. DOption (d)

    (a - b)2 = a2 + b2 - 2ab

View answer & explanation

Correct answer

Answer: (c)C.

(a + b)2 = a2 + b2

Why this answer is correct

Shortcut Trick

An identity must hold true for all values of the variables involved.

Test option 3 with a = 1, b = 1:

LHS = (1 + 1)2 = 22 = 4 | RHS = 12 + 12 = 2

Since 4 ≠ 2, the equation is not an identity.

∴ The correct answer is (a + b)2 = a2 + b2.

Alternate Method

Given: Four mathematical expressions to identify which is not an identity.

Concept: An identity is an equality that remains true regardless of the values chosen for its variables. An equation that is true only for specific values is not an identity.

⇒ Option 1: (a + b)2 = a2 + b2 + 2ab (Standard Algebraic Identity)

⇒ Option 2: (a + 1)(a + 2) = a × a + a × 2 + 1 × a + 1 × 2 = a2 + 3a + 2 (True for all 'a')

⇒ Option 4: (a − b)2 = a2 + b2 − 2ab (Standard Algebraic Identity)

⇒ Option 3: (a + b)2 = a2 + b2

⇒ Expanding LHS: a2 + b2 + 2ab

⇒ Comparing with RHS: a2 + b2 + 2ab ≠ a2 + b2 (unless a × b = 0)

∴ The correct answer is (a + b)2 = a2 + b2.

Additional Information

Algebraic Identity

An equality relation A = B, such that A and B contain some variables and A and B produce the same value as each other regardless of what values are substituted for the variables.

Difference of Squares

A very common identity used in simplification is (a + b)(a − b) = a2 − b2.

Conditional Equations

Equations like x + 2 = 5 are only true for x = 3, hence they are not identities.

Question 15

Which of the following statements regarding saturated and unsaturated carbon compounds is correct?

Statement I: Saturated carbon compounds are hydrocarbons where carbon atoms are connected by single covalent bonds.

Statement II: Unsaturated carbon compounds are hydrocarbons where carbon atoms are connected by single covalent bonds.

  1. AOption (a)

    Only statement I is correct.

  2. BOption (b)

    Neither statement I nor II is correct. 

  3. COption (c)

    Both statements I and II are correct.

  4. DOption (d)

    Only statement II is correct.

View answer & explanation

Correct answer

Answer: (a)A.

Only statement I is correct.

Why this answer is correct

The Correct answer is Only statement I is correct.

Key Points

  • Saturated carbon compounds are hydrocarbons where carbon atoms are connected by single covalent bonds.
  • These compounds are typically alkanes.
  • Unsaturated carbon compounds are hydrocarbons where carbon atoms are connected by double or triple covalent bonds.
  • These compounds include alkenes (with double bonds) and alkynes (with triple bonds).
  • Statement I correctly describes saturated carbon compounds.
  • Statement II incorrectly describes unsaturated carbon compounds as having single covalent bonds, which is characteristic of saturated compounds.

 Additional Information

  • Saturated hydrocarbons
  • These are aliphatic hydrocarbons like methane, ethane, and propane.
  • They are generally less reactive than unsaturated hydrocarbons.
  • Unsaturated hydrocarbons
  • These compounds include ethene (ethylene) and ethyne (acetylene).
  • They are more reactive due to the presence of multiple bonds.

Question 16

Given below is a statement followed by two possible reasons numbered I and II. Read the statement carefully and decide which of the two explain(s) the event/observation/information given in the statement.

Statement - The movement of a person or people from one country, locality, place of residence to settle in another country, locality, place of residence is known as migration.

Reasons:

I. Some person or people migrate in search of work or economic opportunities, to join family, or to study. Others migrate to escape conflict, persecution, terrorism, or human rights violations.

II. Some person or people migrate in response to the adverse effects of climate change, natural disasters, or other environmental factors.

  1. AOption (a)

    Both I and II are possible reasons

  2. BOption (b)

    Neither I nor II is a possible reason.

  3. COption (c)

    Only I is a possible reason.

  4. DOption (d)

    Only II is a possible reason.

View answer & explanation

Correct answer

Answer: (a)A.

Both I and II are possible reasons

Why this answer is correct

The correct answer is Both I and II are possible reasons.

Key Points

  • Migration refers to the movement of a person or people from one country, locality, or place of residence to settle in another.
  • Reason I explains that migration occurs due to various factors such as the search for work, economic opportunities, joining family, or studying. Additionally, people may migrate to escape conflict, persecution, terrorism, or human rights violations.
  • Reason II highlights that migration can also be driven by environmental factors such as the adverse effects of climate change, natural disasters, or other environmental challenges.
  • Both reasons are valid and encompass a wide range of factors that contribute to migration.

 Additional Information

  • Reason I
  • People often migrate for economic opportunities such as better job prospects and higher wages.
  • Family reunification is another important factor where people move to join family members already settled in another region.
  • Many students migrate to pursue higher education and enhance their skills.
  • Migration also occurs as a means to escape conflict, persecution, or human rights violations, ensuring personal safety and security.
  • Reason II
  • Climate change has led to environmental degradation, prompting people to move to safer areas.
  • Natural disasters such as earthquakes, floods, and hurricanes can cause significant displacement.
  • Other environmental factors like desertification and rising sea levels also contribute to migration.

Question 17

Select the INCORRECT pair. 

  1. AOption (a)

    Kulhad — non-biodegradable 

  2. BOption (b)

    Vegetable — biodegradable 

  3. COption (c)

    Plastic glass — non-biodegradable 

  4. DOption (d)

    Paper cup — biodegradable 

View answer & explanation

Correct answer

Answer: (a)A.

Kulhad — non-biodegradable 

Why this answer is correct

The correct answer is Kulhad — non-biodegradable.

Key Points

  • Kulhad is a traditional clay cup commonly used in India for serving tea or other beverages.
  • It is made from natural clay and is therefore biodegradable.
  • Being biodegradable, kulhads can decompose naturally over time and do not harm the environment.
  • This makes kulhads environmentally friendly compared to plastic or other non-biodegradable materials.

 Additional Information

  • Vegetable — biodegradable
  • Vegetables are organic matter and decompose naturally.
  • They are classified as biodegradable because they break down through natural processes.
  • This decomposition enriches the soil with nutrients.
  • Plastic glass — non-biodegradable
  • Plastic glass is made from synthetic materials.
  • It is classified as non-biodegradable because it does not decompose naturally.
  • Improper disposal can lead to environmental pollution.
  • Paper cup — biodegradable
  • Paper cups are made from paper, which is a natural material.
  • They are generally biodegradable and can decompose naturally.
  • However, if coated with plastic, they may not be fully biodegradable.

Question 18

In Δ PQR, ∠Q = ∠R and QR = 12 cm, PR= 10 cm and PS be the altitude, then the length of PS is:

  1. AOption (a)

    11 cm

  2. BOption (b)

    8 cm

  3. COption (c)

    3 cm

  4. DOption (d)

    10 cm

View answer & explanation

Correct answer

Answer: (b)B.

8 cm

Why this answer is correct

Shortcut Trick

Since ∠Q = ∠R, Δ PQR is an Isosceles triangle with PQ = PR = 10 cm.

In an isosceles triangle, the altitude PS bisects the base QR → QS = SR = 12 ÷ 2 = 6 cm.

Using Pythagorean triplet (6, 8, 10) in right-angled Δ PSQ: PS2 + 62 = 102.

PS = √(100 − 36) = √64 = 8 cm.

∴ The correct answer is 8 cm.

Alternate Method

Given: QR = 12 cm, PR = 10 cm, ∠Q = ∠R.

Formula Used: Pythagoras Theorem: Hypotenuse2 = Base2 + Perpendicular2.

⇒ In Δ PQR, as ∠Q = ∠R, sides opposite to equal angles are equal ∴ PQ = PR = 10 cm.

⇒ PS is the altitude to the base QR of an isosceles triangle, so it bisects QR.

⇒ QS = SR = QR ÷ 2 = 12 ÷ 2 = 6 cm.

⇒ In right Δ PSQ, PQ2 = PS2 + QS2.

⇒ 102 = PS2 + 62

⇒ 100 = PS2 + 36

⇒ PS2 = 64

⇒ PS = 8 cm.

∴ The correct answer is 8 cm.

Additional Information

Isosceles Triangle Properties

The altitude from the vertex between equal sides to the base bisects the base and the vertex angle.

Pythagorean Triplets

Common triplets like (3, 4, 5), (6, 8, 10), and (5, 12, 13) help solve right-triangle problems instantly.

Area of Triangle

Area = 1/2 × Base × Height. For this triangle, Area = 1/2 × 12 × 8 = 48 cm2.

Question 19

Which of the following compounds is used in a soda-acid fire extinguisher? 

  1. AOption (a)

    NaHCO3

  2. BOption (b)

    Na2CO3

  3. COption (c)

    H2CO3

  4. DOption (d)

    Ca(OH)2

View answer & explanation

Correct answer

Answer: (a)A.

NaHCO3

Why this answer is correct

The correct answer is NaHCO3.

Key Points

  • NaHCO3 is commonly known as sodium bicarbonate or baking soda.
  • In a soda-acid fire extinguisher, sodium bicarbonate reacts with sulfuric acid to produce carbon dioxide gas.
  • The carbon dioxide gas produced helps to smother the fire by cutting off the oxygen supply.
  • This reaction also produces water, which helps in cooling the fire.
  • Sodium bicarbonate is preferred due to its easy availability, cost-effectiveness, and non-toxic nature.

 Additional Information

  • Na2CO3
  • Sodium carbonate, also known as soda ash or washing soda, is not used in fire extinguishers.
  • It is primarily used in glass manufacturing and as a cleaning agent.
  • H2CO3
  • Carbonic acid is a weak acid formed when carbon dioxide dissolves in water.
  • It is not used in fire extinguishers and is primarily found in carbonated beverages.
  • Ca(OH)2
  • Calcium hydroxide, also known as slaked lime or hydrated lime, is not suitable for fire extinguishers.
  • It is commonly used in construction, water treatment, and agriculture.

Question 20

A ball of mass 0.5 kg is moving with a uniform velocity of 6 m/s. The kinetic energy of the ball is: 

  1. AOption (a)

    9 J

  2. BOption (b)

    12 J

  3. COption (c)

    6 J

  4. DOption (d)

    15 J

View answer & explanation

Correct answer

Answer: (a)A.

9 J

Why this answer is correct

The Correct answer is 9 J.

Key Points

  • The formula to calculate kinetic energy (KE) is KE = 1/2 * m * v², where m is the mass and v is the velocity.
  • Given, mass (m) = 0.5 kg and velocity (v) = 6 m/s.
  • Substituting the values in the formula: KE = 1/2 * 0.5 kg * (6 m/s)².
  • Calculating the velocity squared: (6 m/s)² = 36 m²/s².
  • Now, KE = 1/2 * 0.5 kg * 36 m²/s² = 0.25 kg * 36 m²/s².
  • Finally, KE = 9 J.
  • Therefore, the kinetic energy of the ball is 9 J.

Question 21

If 6 men and 8 boys can do a piece of work in 10 days while 26 men and 48 boys can do the same in 2 days, the time taken by 40 men and 20 boys in doing the same type of work will be:

  1. AOption (a)

    4 days

  2. BOption (b)

    3 days

  3. COption (c)

    5 days

  4. DOption (d)

    2 days

View answer & explanation

Correct answer

Answer: (d)D.

2 days

Why this answer is correct

Shortcut Trick

Equate work: (6M + 8B) × 10 = (26M + 48B) × 2

⇒ 60M + 80B = 52M + 96B ⇒ 8M = 16B ⇒ 1M = 2B

Total Work = (6M + 8B) × 10 = (12B + 8B) × 10 = 200B

Required Efficiency (40M + 20B) = (80B + 20B) = 100B

Time = 200B ÷ 100B = 2 days

∴ The correct answer is 2 days.

Alternate Method

Given:

Case 1: 6 men and 8 boys in 10 days

Case 2: 26 men and 48 boys in 2 days

Formula Used:

M1D1 = M2D2 (where M is the total efficiency and D is time)

PersonDaysTotal WorkEfficiency
(6M + 8B)10200 Units
(26M + 48B)2200 Units100 Units/day

Calculations:

⇒ (6M + 8B) × 10 = (26M + 48B) × 2

⇒ 30M + 40B = 26M + 48B

⇒ 4M = 8B ⇒ 1M = 2B

⇒ Total Work = (6 × 2B + 8B) × 10 = 20B × 10 = 200B units

⇒ Efficiency of 40 men + 20 boys = (40 × 2B + 20B) = 100B units/day

⇒ Time taken = 200B ÷ 100B = 2 days

∴ The correct answer is 2 days.

Additional Information

Man-Day Concept

The amount of work done is proportional to the number of persons and the time taken: W = M × D × H.

Efficiency Ratio

If 1 man = 2 boys, the efficiency ratio of Man to Boy is 2 : 1. Always convert all entities into a single unit (either all Men or all Boys).

Work and Wages

Wages are always distributed in the ratio of the actual work done or the ratio of efficiencies if they work for the same duration.

Question 22

In the following number-pairs, the second number is obtained by applying certain mathematical operations to the first number. Which numbers should replace X and Y so that the pattern followed by the two numbers on the left side of :: is same as that on the right side of ::?

(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 - Operations on 13 such as adding/subtracting multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)

X : 163 :: 74 : Y

  1. AOption (a)

    X = 81, Y = 149

  2. BOption (b)

    X = 79, Y = 145

  3. COption (c)

    X = 86, Y = 129

  4. DOption (d)

    X = 93, Y = 156

View answer & explanation

Correct answer

Answer: (a)A.

X = 81, Y = 149

Why this answer is correct

The logic followed here is:

Logic: (1st number × 2) + 1 = 2nd number.

For, X : 163

⇒ (X × 2) + 1 = 163

⇒ X = (163 - 1) ÷ 2 = 162 ÷ 2 = 81

Similarly, 

For, 74 : Y

⇒ (74 × 2) + 1 = Y

⇒ 148 + 1 = 149

Hence, the correct answer is "Option 1".

Question 23

Select the triad which follows the same pattern as that followed by the two triads given below. Both triads follow the same pattern.

SALT-ALST-TLAS

HOLE -OLHE - ELOH

  1. AOption (a)

    GREW - GERW-WERG

  2. BOption (b)

    FING - INFG-INGF

  3. COption (c)

    VIBE - IBVE - EBIV

  4. DOption (d)

    ROAM - ORAM - MOAR

View answer & explanation

Correct answer

Answer: (c)C.

VIBE - IBVE - EBIV

Why this answer is correct

The logic follows here is,

Given:

SALT-ALST-TLAS

And, HOLE -OLHE - ELOH

Similarly, in option (3): VIBE - IBVE - EBIV

Hence the correct answer is "Option 1"

Question 24

Which of the following is INCORRECTLY matched related to the excretory system of humans?

  1. AOption (a)

    Ureter - a pair

  2. BOption (b)

    Kidney - a pair

  3. COption (c)

    Urinary bladder - unpaired

  4. DOption (d)

    Urethra - a pair

View answer & explanation

Correct answer

Answer: (d)D.

Urethra - a pair

Why this answer is correct

The correct answer is Urethra - a pair.

Key Points

  • The urethra is a tube that carries urine from the urinary bladder to the outside of the body.
  • In males, the urethra also carries semen during ejaculation.
  • Humans have a single urethra, which is unpaired.
  • The female urethra is approximately 4 cm long, while the male urethra is about 20 cm long.
  • The urethra opens at the external urethral orifice, which is located at the tip of the penis in males and above the vaginal opening in females.

 Additional Information

  • Ureter
  • The ureters are a pair of tubes that carry urine from the kidneys to the urinary bladder.
  • Each human body has a pair of ureters, one attached to each kidney.
  • The ureters are approximately 25-30 cm long.
  • They enter the urinary bladder at an oblique angle to prevent the backflow of urine.
  • Kidney
  • Humans have a pair of kidneys, which are vital organs for filtering blood and producing urine.
  • Each kidney is located on either side of the spine, just below the rib cage.
  • Kidneys help in removing waste products and excess substances from the blood.
  • They also regulate electrolyte balance and blood pressure.
  • Urinary bladder
  • The urinary bladder is a hollow, muscular organ that stores urine until it is excreted.
  • It is located in the pelvis, just above and behind the pubic bone.
  • The bladder can hold between 300-500 mL of urine.
  • When it is full, stretch receptors in the bladder signal the brain to initiate the urge to urinate.

Question 25

Which of the following is treated with dry slaked lime [Ca(OH)2] to make bleaching powder?

  1. AOption (a)

    Hydrogen gas

  2. BOption (b)

    Carbon dioxide gas

  3. COption (c)

    Water

  4. DOption (d)

    Chlorine gas

View answer & explanation

Correct answer

Answer: (d)D.

Chlorine gas

Why this answer is correct

The Correct answer is Chlorine gas.

Key Points

  • Bleaching powder is chemically known as calcium hypochlorite (Ca(OCl)₂).
  • It is produced by the action of chlorine gas on dry slaked lime (calcium hydroxide).
  • The chemical reaction involved is: Ca(OH)₂ + Cl₂ → Ca(OCl)₂ + H₂O.
  • Bleaching powder is widely used for disinfecting drinking water and in the textile industry for bleaching fabrics.
  • It is also utilized in the paper industry for bleaching wood pulp.
  • The process of making bleaching powder involves solid-phase reactions where chlorine gas is passed over dry slaked lime.

 Additional Information

  • Hydrogen gas
  • Hydrogen gas is the lightest and most abundant element in the universe.
  • It is commonly used in industrial processes such as ammonia production and hydrogenation of fats and oils.
  • Hydrogen is also being explored as a clean fuel alternative in fuel cells and hydrogen-powered vehicles.
  • Carbon dioxide gas
  • Carbon dioxide (CO₂) is a colorless, odorless gas found in Earth's atmosphere.
  • It is used in various industries, including the beverage industry for carbonation and the food industry for refrigeration and preservation.
  • CO₂ is also a significant greenhouse gas contributing to global warming.
  • Water
  • Water (H₂O) is a universal solvent and essential for all known forms of life.
  • It is used in a wide range of applications including drinking, agriculture, industrial processes, and sanitation.
  • Water is chemically neutral and does not react with slaked lime to produce bleaching powder.

Question 26

Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which pair does not belong to that group?

(Note: The odd one out is not based on the number of consonants/vowels or their position in the letter-cluster.)

  1. AOption (a)

    LP-MQ

  2. BOption (b)

    FJ-GI

  3. COption (c)

    IM-JL

  4. DOption (d)

    QU-RT

View answer & explanation

Correct answer

Answer: (a)A.

LP-MQ

Why this answer is correct

The logic followed here is:

Option 1) LP-MQ

Option 2) FJ-GI

Option 3) IM-JL

Option 4) QU-RT

Thus, out of all the options 'LP-MQ' is the odd one out.

Hence, "Option 1" is the correct answer

Question 27

Which of the following statements is correct about the ozone?

  1. AOption (a)

    Decrease in the amount of ozone in the atmosphere is due to chlorofluorocarbons (CFC).

  2. BOption (b)

    It is not poisonous.

  3. COption (c)

    It is formed by combining only two atoms of oxygen.

  4. DOption (d)

    It causes blood cancer.

View answer & explanation

Correct answer

Answer: (a)A.

Decrease in the amount of ozone in the atmosphere is due to chlorofluorocarbons (CFC).

Why this answer is correct

The correct answer is Decrease in the amount of ozone in the atmosphere is due to chlorofluorocarbons (CFC)..

Key Points

  • Ozone is a molecule composed of three oxygen atoms (O3).
  • Ozone depletion refers to the thinning of the ozone layer in the Earth's stratosphere.
  • Chlorofluorocarbons (CFCs) are the primary cause of ozone layer depletion. CFCs are man-made chemical compounds used in air conditioning, refrigeration, and aerosol propellants.
  • When CFCs are released into the atmosphere, they eventually rise to the stratosphere, where they are broken down by UV radiation, releasing chlorine atoms.
  • The chlorine atoms react with ozone molecules, causing the ozone to break down into oxygen molecules, thus depleting the ozone layer.
  • The Montreal Protocol was established in 1987 to phase out the production and use of substances that deplete the ozone layer, including CFCs.

 Additional Information

  • It is not poisonous.
  • Ozone at ground level is harmful and can cause respiratory problems and other health issues. While in the stratosphere, it is essential for blocking harmful UV radiation.
  • It is formed by combining only two atoms of oxygen.
  • Ozone is actually formed by combining three oxygen atoms (O3), not two. The molecule of two oxygen atoms is regular oxygen (O2).
  • It causes blood cancer.
  • There is no direct evidence linking ozone to blood cancer. However, exposure to high levels of ground-level ozone can cause respiratory problems and other health issues.

Question 28

If x = 32 x 23, then x4 =?

  1. AOption (a)

    36 × 27

  2. BOption (b)

    38 × 23

  3. COption (c)

    36 × 23

  4. DOption (d)

    38 × 212

View answer & explanation

Correct answer

Answer: (d)D.

38 × 212

Why this answer is correct

Given:

x = 32 × 23

Formula used:

(am × bn)p = am×p × bn×p

Calculations:

We need to find the value of x4

⇒ x4 = (32 × 23)4

⇒ x4 = 32×4 × 23×4

⇒ x4 = 38 × 212

∴ The correct answer is option (4).

Question 29

The inverse ratio of 1 : 2 : 3 is:

  1. AOption (a)

    2 : 1 : 3

  2. BOption (b)

    2 : 3 : 6

  3. COption (c)

    3 : 2 : 1

  4. DOption (d)

    6 : 3 : 2

View answer & explanation

Correct answer

Answer: (d)D.

6 : 3 : 2

Why this answer is correct

Shortcut Trick

For a ratio a : b : c, the inverse ratio is (b×c) : (a×c) : (a×b).

Given ratio → 1 : 2 : 3

Inverse parts → (2×3) : (1×3) : (1×2)

⇒ 6 : 3 : 2

∴ The correct answer is 6 : 3 : 2.

Alternate Method

Given: Ratio = 1 : 2 : 3

Formula Used: Inverse ratio of a : b : c is 1/a : 1/b : 1/c

Calculations:

⇒ Inverse ratio = 1/1 : 1/2 : 1/3

⇒ To convert to whole numbers, multiply each term by the LCM of denominators (1, 2, 3) = 6

⇒ (1/1 × 6) : (1/2 × 6) : (1/3 × 6)

⇒ 6 : 3 : 2

∴ The correct answer is 6 : 3 : 2.

Additional Information

Inverse Ratio Property

The inverse ratio (or reciprocal ratio) of a : b is 1/a : 1/b, which simplifies to b : a.

Compound Ratio

The compound ratio of (a : b) and (c : d) is (a×c) : (b×d).

Duplicate and Sub-duplicate Ratio

Duplicate ratio of a : b is a2 : b2, and sub-duplicate ratio is √a : √b.

Question 30

Select the correct option related to the function of auxin in plants. 

  1. AOption (a)

    Make plants insect resistant  

  2. BOption (b)

    Increases stem width 

  3. COption (c)

    Helps the cells to grow longer  

  4. DOption (d)

    Induce flowering 

View answer & explanation

Correct answer

Answer: (c)C.

Helps the cells to grow longer  

Why this answer is correct

The correct answer is Helps the cells to grow longer.

Key Points

  • Auxins are a class of plant hormones that play a crucial role in the growth and development of plants.
  • They are primarily involved in the elongation of cells in the shoots and roots.
  • Auxins stimulate cell elongation by loosening the cell walls, which allows the cells to take up more water and expand.
  • They are also involved in various other plant growth processes such as apical dominance, root initiation, and fruit development.
  • Auxins are produced in the apical meristems (growth regions at the tips of roots and shoots) and are transported to other parts of the plant where they exert their effects.
  • One of the most well-known auxins is Indole-3-acetic acid (IAA), which is naturally occurring in plants.

 Additional Information

  • Make plants insect resistant
  • This function is not related to auxins. Instead, plant resistance to insects is often achieved through genetic modifications or breeding techniques that increase the plant’s natural defenses.
  • Increases stem width
  • Increasing stem width is primarily influenced by another class of plant hormones called gibberellins and cytokinins.
  • Induce flowering
  • While auxins are involved in many growth processes, the induction of flowering is mainly regulated by florigen and other specific flowering hormones.

Question 31

Which of the following reactions is NOT an exothermic reaction? 

  1. AOption (a)

    Dilution of a strong acid 

  2. BOption (b)

    Photosynthesis 

  3. COption (c)

    Respiration 

  4. DOption (d)

    Burning of natural gas 

View answer & explanation

Correct answer

Answer: (b)B.

Photosynthesis 

Why this answer is correct

The Correct answer is Photosynthesis.

Key Points

  • Photosynthesis is an endothermic reaction, meaning it absorbs energy.
  • In this process, plants use sunlight to convert carbon dioxide and water into glucose and oxygen.
  • It requires the input of light energy from the sun, which is absorbed by chlorophyll.
  • Since it absorbs energy rather than releasing it, photosynthesis is not exothermic.
  • This process is crucial for producing organic compounds and maintaining the oxygen levels in the atmosphere.

 Additional Information

  • Dilution of a strong acid
  • This is an exothermic reaction as it releases heat when the strong acid is diluted with water.
  • Respiration
  • Respiration is an exothermic process because it releases energy by breaking down glucose in the presence of oxygen.
  • Burning of natural gas
  • The burning of natural gas is a highly exothermic reaction, releasing a significant amount of heat and light energy.
  • Natural gas primarily consists of methane which combusts to produce carbon dioxide and water.

Question 32

Which of the following processes involves the transfer of a source of energy (food) from outside the body of an organism to inside? 

  1. AOption (a)

    Nutrition 

  2. BOption (b)

    Metabolism

  3. COption (c)

    Transportation 

  4. DOption (d)

    Translocation 

View answer & explanation

Correct answer

Answer: (a)A.

Nutrition 

Why this answer is correct

The Correct answer is Nutrition.

Key Points

  • Nutrition is the process by which organisms obtain and assimilate food.
  • It involves the intake of nutrients from the environment and their incorporation into the body.
  • This process is essential for providing the energy and materials required for growth, reproduction, and maintenance of the organism.
  • Nutrition includes different modes such as autotrophic (self-feeding) and heterotrophic (feeding on others).
  • In humans and animals, nutrition involves the consumption of food, its digestion, and the absorption of nutrients into the bloodstream.

 Additional Information

  • Metabolism
  • Metabolism refers to the biochemical processes that occur within a living organism to maintain life.
  • These processes include the conversion of food to energy, the building of cellular structures, and the elimination of waste products.
  • Transportation
  • Transportation in biology refers to the movement of substances such as nutrients, gases, and wastes within an organism.
  • In plants, it involves the movement of water and nutrients through the xylem and phloem.
  • Translocation
  • Translocation is a specific type of transportation process in plants.
  • It refers to the movement of organic compounds, especially sucrose, from sources (where they are synthesized) to sinks (where they are used or stored).

Question 33

JGOK is related to HEMI in a certain way based on the English alphabetical order. In the same way, TQYU is related to ROWS. To which of the following options is NKSO related, following the same logic?

  1. AOption (a)

    ILQM

  2. BOption (b)

    ILMQ

  3. COption (c)

    LIQM

  4. DOption (d)

    LIMQ

View answer & explanation

Correct answer

Answer: (c)C.

LIQM

Why this answer is correct

The logic followed here is:

JGOK is related to HEMI

TQYU is related to ROWS

Similarly, NKSO will be related:

Hence, the correct answer is "LIQM".

Question 34

Which of the following metals reacts with very dilute nitric acid to evolve hydrogen gas?

  1. AOption (a)

    Mn

  2. BOption (b)

    Al

  3. COption (c)

    Fe

  4. DOption (d)

    Zn

View answer & explanation

Correct answer

Answer: (a)A.

Mn

Why this answer is correct

The correct answer is Manganese (Mn).

Key Points

  • Manganese (Mn) reacts with very dilute nitric acid to evolve hydrogen gas.
  • When dilute nitric acid is used, it acts as a typical acid releasing hydrogen gas.
  • Manganese is a transition metal with the atomic number 25.
  • Unlike other metals, when reacted with very dilute nitric acid, manganese releases hydrogen gas instead of producing nitrogen oxides.
  • In most cases, nitric acid acts as a strong oxidizing agent, but in its dilute form, it can facilitate the release of hydrogen gas with certain metals.

 Additional Information

  • Aluminium (Al)
  • Aluminium reacts with nitric acid to form a passive oxide layer, preventing the release of hydrogen gas.
  • This passive layer makes aluminium resistant to further reaction with nitric acid.
  • Iron (Fe)
  • Iron reacts with nitric acid, but instead of releasing hydrogen gas, it typically forms iron nitrate (Fe(NO₃)₃) and nitrogen oxides (NO or NO₂).
  • Iron does not release hydrogen gas when reacted with nitric acid due to the oxidizing nature of nitric acid.
  • Zinc (Zn)
  • Zinc reacts with nitric acid to form zinc nitrate (Zn(NO₃)₂) and nitrogen oxides (NO or NO₂), rather than releasing hydrogen gas.
  • Like iron, the reaction of zinc with nitric acid results in the formation of nitrogen oxides due to the strong oxidizing properties of nitric acid.

Question 35

In the rear-view mirror of cars, people use which of the following?

  1. AOption (a)

    Plano-convex lens

  2. BOption (b)

    Convex mirror 

  3. COption (c)

    Concave mirror

  4. DOption (d)

    Biconvex lens

View answer & explanation

Correct answer

Answer: (b)B.

Convex mirror 

Why this answer is correct

The correct answer is Convex mirror.

Key Points

  • A convex mirror is used in the rear-view mirrors of cars.
  • Convex mirrors are chosen because they provide a wider field of view compared to flat or concave mirrors.
  • This wider field of view allows drivers to see more of the area behind them, which helps in preventing accidents.
  • Convex mirrors also produce smaller and upright images, which makes it easier for drivers to judge the distance and speed of vehicles approaching from behind.
  • These mirrors are also known as diverging mirrors because they spread out light rays that strike their surface.
  • The use of convex mirrors in vehicles is a safety feature mandated by many automobile safety regulations.

 Additional Information

  • Plano-convex lens
  • A plano-convex lens is a type of lens with one flat surface and one convex surface.
  • These lenses are commonly used in optical instruments such as magnifying glasses, cameras, and projectors.
  • They are not suitable for rear-view mirrors because they do not provide a wide field of view.
  • Concave mirror
  • A concave mirror has an inward-curved reflecting surface and is also known as a converging mirror.
  • These mirrors are used in applications where focused light is needed, such as in torches, headlights, and shaving mirrors.
  • Concave mirrors produce a limited field of view, making them unsuitable for use as rear-view mirrors in vehicles.
  • Biconvex lens
  • A biconvex lens has two outward-curved surfaces.
  • They are commonly used in microscopes and telescopes to focus light and form clear images.
  • Biconvex lenses are not used in rear-view mirrors because they do not offer a wide field of view and can distort the image.

Question 36

The mode of the observations 20, 23, 25, 30, 20, 31, 32, 35, 20, 41, 42, 43, 20 and 20 is:

  1. AOption (a)

    35

  2. BOption (b)

    30

  3. COption (c)

    20

  4. DOption (d)

    40

View answer & explanation

Correct answer

Answer: (c)C.

20

Why this answer is correct

Shortcut Trick

Mode is the value that appears most frequently in a data set.

List frequencies: 23(1), 25(1), 30(1), 31(1), 32(1), 35(1), 41(1), 42(1), 43(1), and 20(5).

Since 20 repeats 5 times (more than any other number), it is the mode.

∴ The correct answer is 20.

Alternate Method

Given: Observations = 20, 23, 25, 30, 20, 31, 32, 35, 20, 41, 42, 43, 20, 20

Formula Used: Mode = Most frequent observation in the series.

Calculations:

⇒ Arranging the data in ascending order: 20, 20, 20, 20, 20, 23, 25, 30, 31, 32, 35, 41, 42, 43

⇒ Frequency of 20 = 5

⇒ Frequency of other terms = 1 each

⇒ Maximum frequency is associated with the term 20.

⇒ Mode = 20

∴ The correct answer is 20.

Additional Information

Empirical Formula

The relationship between Mean, Median, and Mode is given by: Mode = 3 × Median − 2 × Mean.

Bimodal and Multimodal

If two or more values have the same maximum frequency, the distribution is called bimodal or multimodal.

Central Tendency

Mode is one of the three measures of central tendency, primarily used for categorical data to find the most popular item.

Question 37

In a certain code language,

P + Q means ‘P is the father of Q’,

P - Q means ‘P is the son of Q’,

P × Q means ‘P is the wife of Q’

and P ÷ Q means ‘P is the brother of Q’.

Based on the above, how is K related to R if ‘M ÷ N × O + K × L - R'?

  1. AOption (a)

    Daughter

  2. BOption (b)

    Mother

  3. COption (c)

    Son 

  4. DOption (d)

    Son's wife 

View answer & explanation

Correct answer

Answer: (d)D.

Son's wife 

Why this answer is correct

Decoding the Symbols:

Symbol+-×÷
MeaningfathersonWifeBrother

 

Given: M ÷ N × O + K × L - R

It means: P is the brother of N, N is the wife of O, O is the father of L, L is the son of R.

So,  K is the 'Son's wife' of R.

Hence, the correct answer is "Option 4".

Question 38

The weight of an object on the Moon is ______

  1. AOption (a)

    may be greater than or less than depending on the density of the object 

  2. BOption (b)

    less than the weight on the earth  

  3. COption (c)

    greater than the weight on the earth  

  4. DOption (d)

    equal to the weight on the earth 

View answer & explanation

Correct answer

Answer: (b)B.

less than the weight on the earth  

Why this answer is correct

The correct answer is less than the weight on the earth.

Key Points

  • An object’s weight is the force exerted on it due to gravity.
  • The Moon's gravitational force is about 1/6th of the Earth's gravitational force.
  • Thus, an object on the Moon weighs less than it does on Earth.
  • This is because the mass of the Moon is much smaller compared to Earth, leading to a weaker gravitational pull.
  • For example, an object that weighs 60 kg on Earth would weigh only around 10 kg on the Moon.

 Additional Information

  • May be greater than or less than depending on the density of the object
  • This option is incorrect because the weight of an object is determined by the gravitational force, not its density.
  • Weight is a force and is affected by gravity, whereas density is a property of matter and does not change with location.
  • Greater than the weight on the Earth
  • This is incorrect because the Moon's gravitational force is weaker than Earth's.
  • An object cannot weigh more on the Moon compared to Earth due to the lower gravitational pull.
  • Equal to the weight on the Earth
  • This is incorrect as the gravitational force on the Moon is not the same as on Earth.
  • The weight of an object changes with the change in gravitational force.

Question 39

What is the SI unit of momentum? 

  1. AOption (a)

    kg m-1 s-1

  2. BOption (b)

    kg m

  3. COption (c)

    kg m s

  4. DOption (d)

    kg m s-1

View answer & explanation

Correct answer

Answer: (d)D.

kg m s-1

Why this answer is correct

The correct answer is kg m s-1.

Key Points

  • Momentum is a fundamental concept in physics that describes the quantity of motion an object has.
  • It is a vector quantity, meaning it has both magnitude and direction.
  • The formula for momentum (p) is given by p = m × v, where m is the mass of the object and v is its velocity.
  • The SI unit (International System of Units) for mass is kilogram (kg) and for velocity is meters per second (m/s).
  • Therefore, the SI unit of momentum is derived from these two units, resulting in kg m s-1.
  • Understanding momentum is crucial in various fields of physics and engineering, such as in the study of collisions and conservation laws.

 Additional Information

  • kg m-1 s-1
  • This unit is used in the context of viscosity in fluid dynamics, specifically the dynamic viscosity.
  • Dynamic viscosity is a measure of a fluid's resistance to flow.
  • kg m
  • This combination of units does not correspond to a standard physical quantity in the SI system.
  • kg m s
  • This unit is incorrect because it does not account for the squared time unit required for velocity.

Question 40

If 3 : 6 :: 6 : a, what is the value of a?

  1. AOption (a)

    18

  2. BOption (b)

    12

  3. COption (c)

    16

  4. DOption (d)

    36

View answer & explanation

Correct answer

Answer: (b)B.

12

Why this answer is correct

Shortcut Trick

In a continued proportion a : b :: b : c, the product of extremes equals the product of means.

Given 3 : 6 :: 6 : a

Product of extremes = 3 × a

Product of means = 6 × 6 = 36

a = 36 ÷ 3 = 12

∴ The correct answer is 12.

Alternate Method

Given: 3 : 6 :: 6 : a

Formula Used: If w : x :: y : z, then w/x = y/z.

⇒ 3 / 6 = 6 / a

⇒ 1 / 2 = 6 / a

⇒ a = 6 × 2

⇒ a = 12

∴ The correct answer is 12.

Additional Information

Mean Proportional

If a, b, c are in continued proportion, then b is the mean proportional between a and c, where b2 = ac or b = √(ac).

Third Proportional

In the proportion a : b :: b : c, the term c is called the third proportional to a and b, calculated as c = b2 ÷ a.

Fourth Proportional

In the proportion a : b :: c : d, the term d is the fourth proportional, calculated as d = (b × c) ÷ a.

Question 41

The value of 0.0488 ÷ 0.002 = ?

  1. AOption (a)

    18.7

  2. BOption (b)

    13.8

  3. COption (c)

    24.4

  4. DOption (d)

    21.5

View answer & explanation

Correct answer

Answer: (c)C.

24.4

Why this answer is correct

Given:

0.0488 ÷ 0.002

Formula used:

Division of decimals

Calculations:

? = 0.0488 ÷ 0.002

⇒ ? = 48.8 ÷ 2

⇒ ? = 24.4

∴ The correct answer is option (3).

Question 42

Read the given statements and conclusions carefully. You have to take the given statements to be true even if they seem to be at variance from commonly known facts and decide which conclusion(s) logically follow(s) from the given statements.

Statements:

All bulbs are lights.

Some lights are fans.

Conclusions:

(I) Some fans are bulbs.

(II) All bulbs are fans.

  1. AOption (a)

    Neither conclusion (I) nor (II) follows

  2. BOption (b)

    Only conclusion (II) follows

  3. COption (c)

    Only conclusion (I) follows

  4. DOption (d)

    Both conclusions (I) and (II) follow

View answer & explanation

Correct answer

Answer: (a)A.

Neither conclusion (I) nor (II) follows

Why this answer is correct

The least possible Venn diagram:

Conclusion:

I. Some fans are bulbs → False (because no direct relationship given between fans and bulbs so it may be possible not defined)

II. All bulbs are fans → False (because no direct relationship given between fans and bulbs so it may be possible not defined)

So, Neither conclusion (I) nor (II) follows.

Hence, the correct answer is "Option 1".

Question 43

Which of the following is a connective tissue?

  1. AOption (a)

    Cuboidal epithelium

  2. BOption (b)

    Muscle

  3. COption (c)

    Blood

  4. DOption (d)

    Columnar epithelium

View answer & explanation

Correct answer

Answer: (c)C.

Blood

Why this answer is correct

The correct answer is Blood.

Key Points

  • Blood is a type of connective tissue.
  • It consists of cells suspended in a liquid matrix called plasma.
  • Blood performs various essential functions such as transporting oxygen and nutrients to the cells and removing waste products.
  • It also plays a crucial role in the immune system and in regulating body temperature.
  • Components of blood include red blood cells, white blood cells, platelets, and plasma.
  • Red blood cells (RBCs) are responsible for carrying oxygen from the lungs to the rest of the body.
  • White blood cells (WBCs) are involved in protecting the body against infections.
  • Platelets help in blood clotting and wound healing.

 Additional Information

  • Cuboidal Epithelium
  • Cuboidal epithelium is a type of epithelial tissue that consists of cube-shaped cells.
  • It is found in various organs such as the kidney tubules and glands.
  • The primary function of cuboidal epithelium is secretion and absorption.
  • Muscle
  • Muscle tissue is responsible for movement in the body.
  • There are three types of muscle tissues: skeletal, cardiac, and smooth muscle.
  • Skeletal muscles are involved in voluntary movements, while cardiac and smooth muscles control involuntary functions.
  • Columnar Epithelium
  • Columnar epithelium consists of elongated cells that are taller than they are wide.
  • This type of epithelium is found in the digestive tract and is specialized for absorption and secretion.
  • It often contains goblet cells which secrete mucus.

Question 44

The surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 12 cm each. The radius of the sphere is.

  1. AOption (a)

    4 cm

  2. BOption (b)

    12 cm

  3. COption (c)

    8 cm

  4. DOption (d)

    6 cm

View answer & explanation

Correct answer

Answer: (d)D.

6 cm

Why this answer is correct

Shortcut Trick

Curved Surface Area of Cylinder = 2πrh = πdh

Surface Area of Sphere = 4πR2

Given: 4πR2 = π × 12 × 12

4R2 = 144 ⇒ R2 = 36 ⇒ R = 6 cm

∴ The correct answer is 6 cm.

Alternate Method

Given:

Height of cylinder (h) = 12 cm

Diameter of cylinder (d) = 12 cm ⇒ Radius (r) = 6 cm

Formula Used:

Surface Area of Sphere = 4πR2

Curved Surface Area of Cylinder = 2πrh

Calculations:

⇒ Surface Area of Sphere = Curved Surface Area of Cylinder

⇒ 4 × π × R2 = 2 × π × 6 × 12

⇒ 4R2 = 144

⇒ R2 = 144 ÷ 4

⇒ R2 = 36

⇒ R = √36 = 6 cm

∴ The correct answer is 6 cm.

Additional Information

Total Surface Area of Cylinder

The total surface area includes the curved part and two circular bases: TSA = 2πr(h + r).

Volume of Sphere and Cylinder

Volume of Sphere = (4/3)πR3 and Volume of Cylinder = πr2h.

Hemisphere Properties

CSA of Hemisphere = 2πR2 and TSA of Hemisphere = 3πR2.

Question 45

Which of the following is produced when zinc oxide reacts with carbon?

  1. AOption (a)

    Only CO

  2. BOption (b)

    Only Zn

  3. COption (c)

    Both Zn and CO

  4. DOption (d)

    Zn and CO2

View answer & explanation

Correct answer

Answer: (c)C.

Both Zn and CO

Why this answer is correct

The Correct answer is Both Zn and CO

Key Points

  • When zinc oxide reacts with carbon, the process is called reduction. Zinc oxide (ZnO) is reduced by carbon (C) to form zinc (Zn) and carbon monoxide (CO).
  • The chemical reaction can be written as: ZnO + C → Zn + CO
  • This reaction involves the removal of oxygen from zinc oxide, leaving zinc metal and producing carbon monoxide as a byproduct.
  • This reaction occurs at high temperatures, typically in a furnace or reactor, where the carbon acts as a reducing agent, converting zinc oxide into zinc metal while releasing CO gas.

Additional Information

Types of Chemical Reactions-The The basis for different types of reactions is the product formed, the changes that occur, the reactants involved, and so on. Different types of reactions are

  • Combustion reaction
  • Decomposition reaction
  • Neutralization reaction
  • Precipitation or Double-Displacement Reaction

Combustion Reaction-

  • It is a reaction with a combustible material with an oxidizer to give an oxidized product.
  • An oxidizer is a chemical a fuel requires to burn, generally oxygen.
  • For an example of the combustion of magnesium metal.2Mg + O2→2MgO + Heat Here, 2 magnesium atoms react with a molecule of oxygen-producing 2 molecules of the compound magnesium oxide-releasing some heat in the process.

Decomposition Reaction-

  • It is a reaction in which a single component breaks down into multiple products.
  • Certain changes in energy in the environment have to be made like heat, light, or electricity breaking bonds of the compound. for example of the decomposition of calcium carbonate giving out CaO (Quick Lime) which is a major component of cement. CaCO3(s)→CaO(s)+CO2(g) Here, the compound Calcium carbonate when heated breaks down into Calcium Oxide and Carbon Dioxide.

Neutralization Reaction-

  • It is basically the reaction between an acid and a base giving salt and water as the products.
  • The water molecule formed is by the combination of OH- ions and H+ ions. The overall pH of the products when a strong acid and a strong base undergo a neutralization reaction will be 7.
  • Consider the example of the neutralization reaction between Hydrochloric acid and Sodium Hydroxide giving out sodium chloride(Common Salt) and water. HCl + NaOH → NaCl + H2O Here, an acid and a base, Hydrochloric acid and Sodium Hydroxide react in a neutralization reaction to produce Sodium Chloride(Common Salt) and Water as the by-products.

Question 46

Seven people, A, B, E, F, P. Q and R, are sitting in a row, facing north. Only two people sit to the left of B. Only three people sit between B and R. P sits second to the right of B. Only two people sit between P and A. F sits at some place to the right of E but at some place to the left of Q. How many people sit to the right of F?

  1. AOption (a)

    Four

  2. BOption (b)

    One

  3. COption (c)

    Three

  4. DOption (d)

    Two

View answer & explanation

Correct answer

Answer: (c)C.

Three

Why this answer is correct

Given:

Seven people, A, B, E, F, P. Q and R, are sitting in a row, facing north.

Only two people sit to the left of B. Only three people sit between B and R.

P sits second to the right of B.

Only two people sit between P and A.

F sits at some place to the right of E but at some place to the left of Q.

So, 'Three' people sit to the right of F.

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

Question 47

Which of the following statements is/are correct regarding the atomic number of an element?

Statement I: The atomic number of an element represents the number of protons present in the nucleus of an atom.

Statement II: The atomic number of an element represents the number of neutrons present in the nucleus of an atom.

  1. AOption (a)

    Neither statement I nor II is correct.

  2. BOption (b)

    Both statements I and II are correct.

  3. COption (c)

    Only statement I is correct.

  4. DOption (d)

    Only statement II is correct.

View answer & explanation

Correct answer

Answer: (c)C.

Only statement I is correct.

Why this answer is correct

The correct answer is Only statement I is correct.

Key Points

  • Atomic number is a fundamental property of an element that determines its identity.
  • Statement I is correct because the atomic number of an element represents the number of protons present in the nucleus of an atom.
  • Protons carry a positive charge, and the number of protons defines the chemical properties of the element.
  • The atomic number is unique to each element and is used to distinguish one element from another in the periodic table.

 Additional Information

  • Statement II is incorrect because the number of neutrons in an atom's nucleus is not represented by the atomic number but rather contributes to the atomic mass along with the protons.
  • The number of neutrons can vary among atoms of the same element, leading to different isotopes of that element.
  • The atomic number is denoted by the symbol Z and is always a whole number.
  • For example, the atomic number of hydrogen is 1, meaning it has one proton, while the atomic number of carbon is 6, meaning it has six protons.

Question 48

Vacuoles are present mainly of large size in _______

  1. AOption (a)

    bacteria

  2. BOption (b)

    both plant cells and animal cells

  3. COption (c)

    plant cells

  4. DOption (d)

    animal cells

View answer & explanation

Correct answer

Answer: (c)C.

plant cells

Why this answer is correct

The correct answer is plant cells.

Key Points

  • Vacuoles are membrane-bound organelles found in cells.
  • They are primarily present in plant cells and are usually large and central.
  • The main function of vacuoles in plant cells is to maintain turgor pressure, which keeps the plant rigid and upright.
  • Vacuoles store nutrients, waste products, and other substances essential for the cell's survival.
  • In plant cells, the vacuole can occupy up to 90% of the cell's volume.
  • The membrane that surrounds a vacuole is called the tonoplast.
  • Vacuoles also play a role in cell growth by absorbing water and enlarging, which helps the cell to expand.

 Additional Information

  • Bacteria
  • Bacteria are prokaryotic microorganisms that do not have membrane-bound organelles such as vacuoles.
  • They have simpler structures compared to eukaryotic cells and rely on other mechanisms for storage and waste management.
  • Both plant cells and animal cells
  • While both plant and animal cells have vacuoles, they are more prominent and larger in plant cells.
  • In animal cells, vacuoles are smaller and more numerous, serving different functions such as storage and transport.
  • Animal cells
  • Animal cells do have vacuoles, but they are typically smaller and serve different roles compared to those in plant cells.
  • Animal cell vacuoles are involved in processes like sequestering waste products and helping in intracellular digestion.

Question 49

A and B complete a work in 2 days. If A alone can do it in 4 days then, B alone can do 21-times of the same work in ______________(days)

  1. AOption (a)

    85

  2. BOption (b)

    4

  3. COption (c)

    84

  4. DOption (d)

    5

View answer & explanation

Correct answer

Answer: (c)C.

84

Why this answer is correct

Shortcut Trick

Efficiency of B = Combined efficiency − A's efficiency.

If (A + B) takes 2 days and A takes 4 days, then B's efficiency is 1/2 − 1/4 = 1/4.

B alone takes 4 days for 1 unit of work.

For 21-times the work, B will take 4 × 21 = 84 days.

∴ The correct answer is 84 days.

Alternate Method

Given: Time taken by (A + B) = 2 days, Time taken by A = 4 days.

Formula Used: Total Work = LCM of days; Efficiency = Total Work ÷ Time.

PersonDaysTotal WorkEfficiency
A + B242
A41

⇒ Efficiency of B = Efficiency of (A + B) − Efficiency of A

⇒ Efficiency of B = 2 − 1 = 1 unit/day

⇒ New Work = 21 × 4 = 84 units

⇒ Time taken by B = New Work ÷ B's Efficiency = 84 ÷ 1 = 84 days

∴ The correct answer is 84 days.

Additional Information

Combined Work Formula

If A takes 'x' days and B takes 'y' days, together they take (x × y) ÷ (x + y) days.

Work & Time Relationship

Time is directly proportional to the amount of work done when efficiency remains constant (T1/W1 = T2/W2).

Question 50

If ‘A’ stands for ‘÷’, ‘B’ stands for '×’, “C’ stands for ‘+’ and ‘D’ stands for ‘-', what will come in place of the question mark ‘?’ in the following equation? 

85 A 17 C 82 D 11 B 2 = ?

  1. AOption (a)

    65

  2. BOption (b)

    66

  3. COption (c)

    67

  4. DOption (d)

    68

View answer & explanation

Correct answer

Answer: (a)A.

65

Why this answer is correct

Given Equation: 85 A 17 C 82 D 11 B 2 = ?

BODMAS Rule:

Decoding the given information:

AlphabetABCD
Meaning÷×+-

Now replacing the signs from left to right using BODMAS Rule, we get:

⇒ 85 ÷ 17 + 82 - 11 × 2

⇒ 5 + 82 - 11 × 2

⇒ 5 + 82 - 22

⇒ 87 - 22

⇒ 65

Hence, the correct option is "Option 1".

Question 51

Which of the following metals does NOT react with cold water? 

  1. AOption (a)

    Potassium 

  2. BOption (b)

    Sodium 

  3. COption (c)

    Calcium 

  4. DOption (d)

    Magnesium 

View answer & explanation

Correct answer

Answer: (d)D.

Magnesium 

Why this answer is correct

The correct answer is Magnesium.

Key Points

  • Magnesium is a metal that does not react with cold water.
  • It only reacts with hot water or steam to produce magnesium hydroxide and hydrogen gas.
  • The reaction of magnesium with water is much slower compared to other metals like potassium, sodium, and calcium.
  • Magnesium forms a protective layer of magnesium hydroxide on its surface, which prevents further reaction with water.
  • This characteristic makes magnesium less reactive with cold water.

 Additional Information

  • Potassium
  • Potassium reacts very vigorously with cold water, producing potassium hydroxide and hydrogen gas.
  • The reaction is exothermic and can ignite the hydrogen gas produced.
  • Sodium
  • Sodium also reacts vigorously with cold water, forming sodium hydroxide and hydrogen gas.
  • Similar to potassium, the reaction is exothermic and can ignite the hydrogen gas.
  • Calcium
  • Calcium reacts with cold water to produce calcium hydroxide and hydrogen gas, but the reaction is less vigorous compared to potassium and sodium.

Question 52

Which of the following forts, India's nomination for the UNESCO World Heritage List for 2024-25, was the site of the coronation of Shivaji Maharaj? 

  1. AOption (a)

    Raigad Fort 

  2. BOption (b)

    Karnala Fort

  3. COption (c)

    Korigad Fort 

  4. DOption (d)

    Mangi-Tungi Fort

View answer & explanation

Correct answer

Answer: (a)A.

Raigad Fort 

Why this answer is correct

The Correct answer is Raigad Fort.

Key Points

  • Raigad Fort is located in the Raigad district of Maharashtra.
  • This fort is historically significant as it was the site of the coronation of Chhatrapati Shivaji Maharaj, the founder of the Maratha Empire, in 1674.
  • The fort is situated at an altitude of 2,700 feet above sea level, offering a strategic vantage point.
  • Raigad Fort was originally known as Rairi and was renamed by Shivaji Maharaj.
  • The fort is known for its impressive architecture and includes features such as the Queen's quarters, public Durbar, watchtowers, and several gateways.
  • It played a crucial role in the history of the Maratha Empire and is considered a symbol of Maratha pride and heritage.

 Additional Information

  • Karnala Fort
  • Karnala Fort is located in the Raigad district of Maharashtra.
  • This fort is also known as the Funnel Hill and is a popular trekking destination.
  • Karnala Fort is situated within the Karnala Bird Sanctuary and offers a habitat for various bird species.
  • Korigad Fort
  • Korigad Fort is situated near Lonavala in Maharashtra.
  • The fort is known for its scenic views and has a large plateau with two lakes at the top.
  • Korigad Fort was incorporated into the kingdom of Chhatrapati Shivaji Maharaj in 1657.
  • Mangi-Tungi Fort
  • Mangi-Tungi is a prominent twin-pinnacle peak located in the Nashik district of Maharashtra.
  • This site is a significant Jain pilgrimage destination and is known for its ancient temples and sculptures.
  • The fort is situated at an elevation of 4,343 feet above sea level.

Question 53

In the following number-pairs, the second number is obtained by applying certain mathematical operations to the first number. Which numbers should replace X and Y so that the pattern followed by the two numbers on the left side of :: is the same as that on the right side of ::?

(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 - Operations on 13 such as adding/subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)

X : 75 :: 29 : Y

  1. AOption (a)

    X = 23, Y = 81

  2. BOption (b)

    X = 28, Y = 74

  3. COption (c)

    X = 21, Y = 89

  4. DOption (d)

    X = 26, Y = 76

View answer & explanation

Correct answer

Answer: (a)A.

X = 23, Y = 81

Why this answer is correct

The logic followed here is:

Logic: 1st number + 52 = 2nd number.

For, X : 75

⇒ X + 52 = 75

⇒ X = 75 - 52 = 23.

Similarly, 

For, 29 : Y

⇒ 29 + 52 = 81.

Hence, the correct answer is "Option 1".

Question 54

Who, along with Parthiv Dhar, won the Best Book on Cinema award for 'Kishore Kumar: The Ultimate Biography', as announced by the Ministry of Information & Broadcasting in October 2024?

  1. AOption (a)

    Heena Choudhary

  2. BOption (b)

    Anirudha Bhattacharjee

  3. COption (c)

    Sutapa Chakraborty

  4. DOption (d)

    Nayanjyoti Sarma

View answer & explanation

Correct answer

Answer: (b)B.

Anirudha Bhattacharjee

Why this answer is correct

The correct answer is Anirudha Bhattacharjee.

Key Points

  • Anirudha Bhattacharjee is a well-known author and film historian.
  • He co-authored the book 'Kishore Kumar: The Ultimate Biography' with Parthiv Dhar.
  • The book provides a comprehensive look at the life and career of Kishore Kumar, one of India's most beloved playback singers and actors.
  • The Ministry of Information & Broadcasting of India announced the award in October 2024.
  • The book was awarded the Best Book on Cinema for its in-depth research and engaging narrative.
  • Anirudha Bhattacharjee has previously co-authored other significant works on Indian cinema, including books on R.D. Burman and S.D. Burman.

Question 55

Accumulation of which substance in our muscles during sudden activity causes cramps? 

  1. AOption (a)

    Sucrose

  2. BOption (b)

    Lactic acid

  3. COption (c)

    Glucose

  4. DOption (d)

    Pyruvic acid

View answer & explanation

Correct answer

Answer: (b)B.

Lactic acid

Why this answer is correct

The correct answer is Lactic acid.

Key Points

  • Lactic acid accumulates in muscles during intense exercise or sudden activity.
  • This happens because of anaerobic respiration, where glucose is broken down without oxygen to produce energy.
  • The buildup of lactic acid leads to a condition known as muscle acidosis, causing cramps and fatigue.
  • This process is typically a temporary response to high-intensity exercise.
  • The body usually clears out lactic acid through the bloodstream once the activity level decreases and oxygen becomes available.

 Additional Information

  • Sucrose
  • Sucrose is a common sugar found in many plants and is used as a sweetener in foods and beverages.
  • It does not accumulate in muscles nor cause cramps during physical activity.
  • Glucose
  • Glucose is the primary source of energy for the body's cells.
  • During exercise, glucose is broken down to produce energy, but it does not directly cause cramps.
  • Pyruvic acid
  • Pyruvic acid is an intermediate product in the breakdown of glucose during cellular respiration.
  • It does not accumulate in muscles during exercise; instead, it is converted to lactic acid under anaerobic conditions.

Question 56

What digit must be assigned to k so that the 7-digit number 451k603 is exactly divisible by 9?

  1. AOption (a)

    8

  2. BOption (b)

    7

  3. COption (c)

    5

  4. DOption (d)

    2

View answer & explanation

Correct answer

Answer: (a)A.

8

Why this answer is correct

Given:

The 7-digit number is 451k603.

Formula Used:

A number is divisible by 9 if the sum of its digits is divisible by 9.

Calculation:

Sum of the digits of 451k603 = 4 + 5 + 1 + k + 6 + 0 + 3

Sum = 19 + k

For 451k603 to be divisible by 9, 19 + k must be divisible by 9.

Find the smallest value of k that makes 19 + k divisible by 9:

19 + k = 27

⇒ k = 27 - 19

⇒ k = 8

The correct answer is option 1.

Question 57

Prime Minister Narendra Modi inaugurated PARAM Rudra Supercomputer at which of the following places in September 2024?

  1. AOption (a)

    Hyderabad

  2. BOption (b)

    Chennai 

  3. COption (c)

    Bengaluru 

  4. DOption (d)

    Kolkata

View answer & explanation

Correct answer

Answer: (d)D.

Kolkata

Why this answer is correct

The correct answer is Kolkata.

Key Points

  • Prime Minister Narendra Modi inaugurated the PARAM Rudra Supercomputer in September 2024.
  • The event took place in Kolkata, a major city in the eastern part of India.
  • The PARAM Rudra is part of the National Supercomputing Mission, which aims to enhance India's computational capabilities.
  • This supercomputer is expected to significantly boost research and development in various fields such as climate modeling, computational biology, and material science.
  • PARAM is a series of supercomputers developed by the Centre for Development of Advanced Computing (C-DAC).
  • The name PARAM signifies supreme in Sanskrit.
  • Kolkata is known as the cultural capital of India and has been a center for education, science, and technology.

 Additional Information

  • Hyderabad
  • Hyderabad is known for its Information Technology industry and is often referred to as Cyberabad.
  • The city is home to major IT firms and the Hyderabad Information Technology and Engineering Consultancy City (HITEC City).
  • It is the capital city of the Indian state of Telangana.
  • Chennai
  • Chennai is the capital of the Indian state of Tamil Nadu.
  • It is known for its strong automobile industry and is often referred to as the Detroit of India.
  • Chennai is also a major center for education and healthcare in South India.
  • Bengaluru
  • Bengaluru is known as the Silicon Valley of India due to its role as the nation's leading information technology (IT) exporter.
  • It is the capital of the Indian state of Karnataka.
  • The city is also known for its green spaces and pleasant climate.

Question 58

Which tissue is responsible for the movement in our body? 

  1. AOption (a)

    Epithelial tissue 

  2. BOption (b)

    Cartilage 

  3. COption (c)

    Muscular tissue  

  4. DOption (d)

    Areolar tissue  

View answer & explanation

Correct answer

Answer: (c)C.

Muscular tissue  

Why this answer is correct

The correct answer is Muscular tissue.

Key Points

  • Muscular tissue is responsible for the movement in our body.
  • There are three types of muscular tissue: skeletal, smooth, and cardiac muscles.
  • Skeletal muscles are attached to bones and are responsible for voluntary movements.
  • Smooth muscles are found in the walls of internal organs and help in involuntary movements such as digestion.
  • Cardiac muscles are found in the heart and are responsible for pumping blood throughout the body.
  • Muscular tissues can contract and relax, which allows them to produce movement.

 Additional Information

  • Epithelial tissue
  • Epithelial tissue covers the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.
  • It acts as a barrier to protect the body from outside invaders and helps in absorption, secretion, and sensation.
  • Cartilage
  • Cartilage is a flexible connective tissue found in various parts of the body including joints, ear, nose, and bronchial tubes.
  • It provides support and cushioning in the joints and reduces friction between bones.
  • Areolar tissue
  • Areolar tissue is a type of connective tissue that holds organs in place and attaches epithelial tissue to underlying tissues.
  • It also serves as a reservoir of water and salts for surrounding tissues.

Question 59

The areas of three adjacent faces of a solid cuboid are 66 cm2, 192 cm2 and 198 cm2. What is the volume (in cm3) of the cuboid?

  1. AOption (a)

    1792

  2. BOption (b)

    1594

  3. COption (c)

    1782

  4. DOption (d)

    1584

View answer & explanation

Correct answer

Answer: (d)D.

1584

Why this answer is correct

Shortcut Trick

For a cuboid, if the areas of three adjacent faces are x, y, and z, then the Volume (V) is given by √(x × y × z).

Given areas: x = 66, y = 192, z = 198

V = √(66 × 192 × 198) = √(66 × 192 × (66 × 3)) = 66 × √(192 × 3) = 66 × √576 = 66 × 24

V = 1584 cm3

∴ The correct answer is 1584 cm3.

Alternate Method

Given:

Area of face 1 (lb) = 66 cm2

Area of face 2 (bh) = 192 cm2

Area of face 3 (lh) = 198 cm2

Formula Used:

Volume of cuboid (V) = length (l) × breadth (b) × height (h)

Calculations:

⇒ (lb) × (bh) × (lh) = 66 × 192 × 198

⇒ l2b2h2 = 66 × 192 × 198

⇒ (lbh)2 = 66 × 192 × (66 × 3)

⇒ V2 = 662 × (192 × 3)

⇒ V2 = 662 × 576

⇒ V = √(662 × 242)

⇒ V = 66 × 24 = 1584 cm3

∴ The correct answer is 1584 cm3.

Additional Information

Total Surface Area of Cuboid

The total surface area is given by the formula 2(lb + bh + lh), where l, b, and h are length, breadth, and height.

Diagonal of a Cuboid

The length of the longest rod that can be placed in a cuboid is the diagonal, given by √(l2 + b2 + h2).

Volume and Product of Face Areas

If A1, A2, and A3 are areas of three adjacent faces, then Volume V = √(A1 × A2 × A3).

Question 60

The Finance Minister launched Nari Shakti branches of which bank to empower women entrepreneurs in November 2024?

  1. AOption (a)

    HDFC Bank

  2. BOption (b)

    Union Bank

  3. COption (c)

    PNB

  4. DOption (d)

    SBI

View answer & explanation

Correct answer

Answer: (b)B.

Union Bank

Why this answer is correct

The Correct answer is Union Bank.

Key Points

  • The Finance Minister launched the Nari Shakti branches of Union Bank to empower women entrepreneurs in November 2024.
  • The initiative aims to provide financial services and support to women-led businesses.
  • These branches are designed to cater specifically to the needs of women entrepreneurs, offering tailored financial products and services.
  • The launch of these branches is part of a broader effort to encourage and support women in the business sector.
  • Union Bank of India is one of the largest government-owned banks in India, with a significant focus on inclusive banking.

 Additional Information

  • HDFC Bank
  • HDFC Bank is one of India's leading private sector banks.
  • It is known for its extensive range of financial products and services.
  • While it supports various initiatives, the Nari Shakti branches were not launched under this bank.
  • PNB
  • Punjab National Bank (PNB) is one of the oldest and largest government-owned banks in India.
  • It offers a wide range of banking services but was not the bank associated with the Nari Shakti initiative.
  • SBI
  • State Bank of India (SBI) is the largest bank in India and a public sector banking and financial services company.
  • Although SBI has numerous initiatives for women, the specific Nari Shakti branches were not launched by this bank.

Question 61

What is the colour of the flame when magnesium burns in air?

  1. AOption (a)

    White

  2. BOption (b)

    Pink

  3. COption (c)

    Green

  4. DOption (d)

    Red

View answer & explanation

Correct answer

Answer: (a)A.

White

Why this answer is correct

The correct answer is White.

Key Points

  • When magnesium burns in air, it produces a bright white flame.
  • This white flame is due to the formation of magnesium oxide (MgO).
  • Magnesium has a high affinity for oxygen, leading to a highly exothermic reaction.
  • The bright white light produced is so intense that it can cause temporary blindness if viewed directly.
  • Because of this intense white light, magnesium is often used in pyrotechnics and photographic flashbulbs.

 Additional Information

  • Pink
  • Pink flames are not typically associated with the burning of metals like magnesium.
  • In the context of flames, pink could be indicative of the presence of lithium compounds.
  • Green
  • Green flames are usually produced by the presence of copper compounds.
  • For example, copper chloride can produce a green flame.
  • Red
  • Red flames are often produced by the presence of strontium compounds.
  • Strontium chloride is known to give a bright red flame.

Question 62

A cube-shaped metal box of 1 kg mass is kept on the horizontal surface of a table. Assuming acceleration due to gravity is 10 m/sec2, the thrust acting on the table surface is _______.

  1. AOption (a)

    100 N

  2. BOption (b)

    1 N

  3. COption (c)

    1000 N

  4. DOption (d)

    10 N

View answer & explanation

Correct answer

Answer: (d)D.

10 N

Why this answer is correct

The correct answer is 10 N.

Key Points

  • The thrust acting on the table surface is equal to the weight of the metal box.
  • The weight of an object can be calculated using the formula Weight (W) = mass (m) x acceleration due to gravity (g).
  • Here, the mass (m) of the metal box is 1 kg.
  • The acceleration due to gravity (g) is given as 10 m/sec2.
  • Therefore, the weight (W) = 1 kg x 10 m/sec2 = 10 N.
  • Hence, the thrust acting on the table surface is 10 N.

 Additional Information

  • Thrust
  • Thrust is the force exerted by an object perpendicular to the surface it is in contact with.
  • In the context of weight, it is the gravitational force acting downward due to the object's mass.
  • Weight
  • Weight is a measure of the force exerted by gravity on an object.
  • It is dependent on both the mass of the object and the local gravitational field strength.

Question 63

Which organ of the human body pumps blood?

  1. AOption (a)

    Pancreas

  2. BOption (b)

    Heart

  3. COption (c)

    Stomach

  4. DOption (d)

    Liver

View answer & explanation

Correct answer

Answer: (b)B.

Heart

Why this answer is correct

The correct answer is Heart.

Key Points

  • The heart is a muscular organ located in the chest cavity.
  • It is responsible for pumping blood throughout the body via the circulatory system.
  • The heart ensures the continuous supply of oxygen and nutrients to tissues and organs.
  • The heart operates through a series of rhythmic contractions, regulated by electrical impulses.
  • It consists of four chambers: the right atrium, right ventricle, left atrium, and left ventricle.
  • The heart's activity is vital for maintaining homeostasis and supporting life.

 Additional Information

  • Pancreas
  • The pancreas is a gland located behind the stomach.
  • It plays a crucial role in digestive and endocrine functions.
  • The pancreas produces digestive enzymes and hormones such as insulin.
  • Stomach
  • The stomach is a muscular organ involved in the digestion of food.
  • It secretes gastric juices that aid in breaking down food.
  • The stomach's environment is highly acidic, which helps in killing harmful bacteria.
  • Liver
  • The liver is a vital organ located in the upper right quadrant of the abdomen.
  • It performs various functions including detoxification, protein synthesis, and production of bile.
  • The liver also plays a role in metabolism and regulation of blood sugar levels.

Question 64

The value of −53\frac{-5}{3} × 925\frac{9}{25} + (15\frac{1}{5} - 3) = ?

  1. AOption (a)

    95\frac{9}{5}

  2. BOption (b)

    −45\frac{-4}{5}

  3. COption (c)

    0

  4. DOption (d)

    −175\frac{-17}{5}

View answer & explanation

Correct answer

Answer: (d)D.

−175\frac{-17}{5}

Why this answer is correct

Given:

(-5/3) × (9/25) + (1/5 − 3)

Formula used:

BODMAS rule (Bracket, Of, Division, Multiplication, Addition, Subtraction)

Calculations:

Solving the expression step by step:

⇒ [(-5/3) × (9/25)] + (1/5 − 3)

First, calculate the multiplication part:

⇒ [(-1/1) × (3/5)] + (1/5 − 3)

⇒ (-3/5) + (1/5 − 3)

Now, solve the bracket part:

⇒ (-3/5) + [(1 − 15)/5]

⇒ (-3/5) + (-14/5)

Combine the fractions:

⇒ (-3 − 14)/5

⇒ -17/5

∴ The correct answer is option (4).

Question 65

Which animal was declared the official mascot of 2024 Khelo India Winter Games?

  1. AOption (a)

    Sheep

  2. BOption (b)

    Yak 

  3. COption (c)

    Snow bear

  4. DOption (d)

    Snow leopard

View answer & explanation

Correct answer

Answer: (d)D.

Snow leopard

Why this answer is correct

The Correct answer is Snow leopard.

Key Points

  • The Snow leopard is a large cat native to the mountain ranges of Central and South Asia.
  • It has been listed as Vulnerable on the IUCN Red List because the global population is estimated to number fewer than 10,000 mature individuals and continues to decline.
  • Snow leopards are well adapted to their cold environment with thick fur, small rounded ears, and wide, fur-covered paws that act as natural snowshoes.
  • The species is distributed across 12 countries including China, India, Mongolia, and Russia.
  • In India, they are found in the states of Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh.
  • The snow leopard is an apex predator in its habitat, playing a crucial role in maintaining the balance of the ecosystem.

 Additional Information

  • Yak
  • The Yak is a long-haired domesticated bovid found throughout the Himalayan region of the Indian subcontinent, the Tibetan Plateau, and as far north as Mongolia and Russia.
  • Yaks are used for a variety of purposes including transportation, milk production, and meat.
  • Sheep
  • Sheep are domesticated ruminant mammals typically kept as livestock. They are raised for their wool, meat, and milk.
  • There are numerous breeds of sheep adapted to various climates around the world.
  • Snow bear
  • Snow bears, or more commonly known as Polar bears, are native to the Arctic region.
  • They are classified as marine mammals because they spend most of their lives on the sea ice of the Arctic Ocean.
  • Polar bears are apex predators in their ecosystem, primarily feeding on seals.

Question 66

The founder and chairman of which of the following companies topped the EdelGive-Hurun India Philanthropy List 2024?

  1. AOption (a)

    HCL Technologies

  2. BOption (b)

    Reliance Industries 

  3. COption (c)

    WIPRO

  4. DOption (d)

    TCS

View answer & explanation

Correct answer

Answer: (a)A.

HCL Technologies

Why this answer is correct

The Correct answer is HCL Technologies.

Key Points

  • HCL Technologies is an Indian multinational information technology (IT) services and consulting company.
  • The founder and chairman of HCL Technologies is Shiv Nadar.
  • Shiv Nadar has topped the EdelGive-Hurun India Philanthropy List 2024, recognizing his significant contributions to philanthropy.
  • HCL Technologies is headquartered in Noida, India.
  • The company operates in over 50 countries and has a worldwide network of R&D, innovation labs, and delivery centers.
  • HCL Technologies provides services including software development, business process outsourcing (BPO), and IT infrastructure management.
  • The company is one of the top IT services companies in India and is known for its innovation and customer-centric approach.

 Additional Information

  • Reliance Industries
  • Reliance Industries is an Indian multinational conglomerate company headquartered in Mumbai, India.
  • The company is involved in businesses across sectors such as petrochemicals, refining, oil, telecommunications, and retail.
  • It is one of the largest companies in India in terms of market capitalization and revenue.
  • WIPRO
  • WIPRO Limited is an Indian multinational corporation that provides information technology, consulting, and business process services.
  • Headquartered in Bengaluru, India, WIPRO is one of the largest IT services companies in India.
  • It was founded by Mohamed Premji in 1945.
  • TCS
  • Tata Consultancy Services (TCS) is an Indian multinational information technology services and consulting company.
  • It is headquartered in Mumbai, India, and operates in 46 countries.
  • TCS is a part of the Tata Group, one of India's largest and oldest industrial conglomerates.

Question 67

A shopkeeper allows a 4% discount on his marked price. If the cost price of an article is ₹120 and he has to make a profit of 10%, then his marked price must be:

  1. AOption (a)

    ₹120.50

  2. BOption (b)

    ₹137.50

  3. COption (c)

    ₹117.50

  4. DOption (d)

    ₹127.50

View answer & explanation

Correct answer

Answer: (b)B.

₹137.50

Why this answer is correct

Shortcut Trick

The relation between Marked Price (MP) and Cost Price (CP) is given by: MP ÷ CP = (100 + Profit%) ÷ (100 − Discount%).

MP ÷ 120 = (100 + 10) ÷ (100 − 4)

MP ÷ 120 = 110 ÷ 96

MP = (110 × 120) ÷ 96

MP = 13200 ÷ 96 = 137.50

∴ The correct answer is ₹137.50.

Alternate Method

Given: CP = ₹120, Profit% = 10%, Discount% = 4%.

Formulas: SP = CP × (100 + P%) ÷ 100 | MP = (SP × 100) ÷ (100 − D%)

⇒ Selling Price (SP) = 120 × (110 ÷ 100) = 132

⇒ Marked Price (MP) × (100 − 4) ÷ 100 = 132

⇒ MP × 0.96 = 132

⇒ MP = 132 ÷ 0.96 = 137.50

∴ The correct answer is ₹137.50.

Additional Information

Marked Price and Discount

The Marked Price is the price printed on the label, and Discount is always calculated on the MP to arrive at the Selling Price.

MP-CP Ratio Formula

The direct ratio MP/CP = (100 + P%)/(100 - D%) is the most efficient way to solve problems involving both discount and profit.

Question 68

Refer to the given series and answer the question that follows (all numbers are single-digit numbers only, and all counting is to be done from left to right).

(Left) 8 7 7 8 5 2 7 1 4 3 2 4 7 7 6 4 5 3 1 2 6 7 9 7 9 8 0 1 3 3 (Right)

How many such odd digits are there, each of which is immediately preceded by a perfect square and immediately followed by an even digit? (Note: I will be considered as a perfect square.)

  1. AOption (a)

    1

  2. BOption (b)

    4

  3. COption (c)

    3

  4. DOption (d)

    2

View answer & explanation

Correct answer

Answer: (a)A.

1

Why this answer is correct

Given series:

(Left) 8 7 7 8 5 2 7 1 4 3 2 4 7 7 6 4 5 3 1 2 6 7 9 7 9 8 0 1 3 3 (Right)

Condition to be checked:

Perfect square → Odd digits → Even digit

(Left) 8 7 7 8 5 2 7 1 4 3 2 4 7 7 6 4 5 3 1 2 6 7 9 7 9 8 0 1 3 3 (Right)

Thus there is one such pattern (4 3 2) that is following the above conditions.

Hence, "1" is the correct answer.

Mistake Points

Immediately preceded by means immediately before or to come just before.

Immediately followed by means immediately after or to come just after.

Question 69

Which of the following options should come in place of the question mark (?) in the given series to make it logically complete?

78, 124, 152, 198, 226, 272, ?

  1. AOption (a)

    294

  2. BOption (b)

    286

  3. COption (c)

    320

  4. DOption (d)

    300

View answer & explanation

Correct answer

Answer: (d)D.

300

Why this answer is correct

The logic follows here:

Hence, the correct answer is "Option (4)".

Question 70

If 'A' stands for '÷', 'B' stands for '×', 'C' stands for '+' and 'D' stands for '-', what will be come in place of the question mark '?' in the following equation?

(14 B 4) A 2 C (15 A 5) B 9 D 34 C (48 A 6) B 2 = ?

  1. AOption (a)

    37

  2. BOption (b)

    22

  3. COption (c)

    17

  4. DOption (d)

    45

View answer & explanation

Correct answer

Answer: (a)A.

37

Why this answer is correct

Given Equation: (14 B 4) A 2 C (15 A 5) B 9 D 34 C (48 A 6) B 2 = ?

BODMAS Rule:

Decoding the given information:

AlphabetABCD
Meaning÷×+-

Now replacing the signs from left to right using BODMAS Rule, we get:

⇒ (14 × 4) ÷ 2 + (15 ÷ 5) × 9 - 34 + (48 ÷ 6) × 2

⇒ 56 ÷ 2 + 3 × 9 - 34 + 8 × 2

⇒ 28 + 3 × 9 - 34 + 8 × 2

⇒ 28 + 27 - 34 + 16

⇒ 71 - 34

⇒ 37

Hence, the correct option is "Option 1".

Question 71

Refer to the given number and symbol series and answer the question that follows. Counting to be done from left to right only.

(Left) & 3 Ω # 2 & % 4 6 @ 8 $ 7 1 * £ 5 (Right)

If all the symbols are dropped from the series, which of the following will be seventh from the right$?

  1. AOption (a)

    7

  2. BOption (b)

    1

  3. COption (c)

    2

  4. DOption (d)

    9

View answer & explanation

Correct answer

Answer: (c)C.

2

Why this answer is correct

Given series:

(Left) & 3 Ω # 2 & % 4 6 @ 8 $ 7 1 * £ 5 (Right)

If all the symbols are dropped from the series, the remaining series will be:

(Left) 3 2 4 6 8 7 1 5 (Right)

Counting from the right, the seventh element is:

(Left) 3 2 4 6 8 7 1 5 (Right)

Seventh from the right: 2

Hence, the correct answer is "Option (3)"$.

Question 72

What sum will earn a simple interest of Rs. 960 in 3 years at 16% per year rate of interest?

  1. AOption (a)

    Rs. 1800

  2. BOption (b)

    Rs. 2000

  3. COption (c)

    Rs. 2200

  4. DOption (d)

    Rs. 1600

View answer & explanation

Correct answer

Answer: (b)B.

Rs. 2000

Why this answer is correct

Shortcut Trick

Effective Rate of Interest for 3 years = 16% × 3 = 48%.

Given, 48% of Principal = ₹960.

1% = 960 ÷ 48 = 20.

100% (Principal) = 20 × 100 = ₹2000.

∴ The correct answer is ₹2000.

Alternate Method

Given:

Simple Interest (SI) = ₹960

Time (T) = 3 years

Rate (R) = 16% per annum

Formula Used:

Simple Interest (SI) = (P × R × T) ÷ 100

Calculations:

⇒ 960 = (P × 16 × 3) ÷ 100

⇒ 960 = (P × 48) ÷ 100

⇒ 48 × P = 960 × 100

⇒ P = 96000 ÷ 48

⇒ P = ₹2000

∴ The correct answer is ₹2000.

Additional Information

Definition of Simple Interest

It is the interest calculated only on the original principal amount for every period. SI = (P × R × T) ÷ 100.

Total Amount Formula

The total Amount (A) after T years is the sum of Principal and Simple Interest. A = P + SI = P[1 + (RT/100)].

Relationship between SI and Rate

For a constant principal and time, Simple Interest is directly proportional to the Rate of Interest.

Question 73

A train of 24 carriages, each of 60 m length, while an engine also of 60 m length is running at a speed of 50 km/h. In how much time will the train cross a bridge 1.5 km long?

  1. AOption (a)

    3 min

  2. BOption (b)

    4.4 min

  3. COption (c)

    3.6 min

  4. DOption (d)

    4 min

View answer & explanation

Correct answer

Answer: (c)C.

3.6 min

Why this answer is correct

Shortcut Trick

Total length = (24 carriages + 1 engine) × 60 m + 1.5 km = 25 × 60 + 1500 = 3000 m.

Speed = 50 km/h = 50 × (5/18) m/s.

Time = Distance ÷ Speed = 3000 ÷ (250/18) = 12 × 18 = 216 seconds.

Time in minutes = 216 ÷ 60 = 3.6 min.

∴ The correct answer is 3.6 min.

Alternate Method

Given:

Number of carriages = 24, Number of engines = 1

Length of each unit = 60 m, Length of bridge = 1.5 km = 1500 m

Speed of train = 50 km/h

Calculations:

⇒ Total length of train = (24 + 1) × 60 = 25 × 60 = 1500 m

⇒ Total distance to cover = Length of train + Length of bridge = 1500 + 1500 = 3000 m

⇒ Speed in m/s = 50 × (5/18) = 250/18 m/s

⇒ Time taken (seconds) = 3000 ÷ (250/18) = (3000 × 18) ÷ 250 = 12 × 18 = 216 sec

⇒ Time in minutes = 216 ÷ 60 = 3.6 min

∴ The correct answer is 3.6 min.

Additional Information

Unit Conversion

To convert speed from km/h to m/s, multiply by 5/18. To convert m/s to km/h, multiply by 18/5.

Crossing Distance Rule

When a train crosses a platform, bridge, or another train, the total distance is the sum of the lengths of the train and the object.

Relative Speed

For two objects moving in the same direction, relative speed = S1 − S2. In opposite directions, relative speed = S1 + S2.

Question 74

If each vowel in the word MAJORITY is changed to the letter following it in the English alphabetical order and each consonant is changed to the letter preceding it in the English alphabetical order, then how many letters are common between the original word and the group of letters thus formed?

  1. AOption (a)

    1

  2. BOption (b)

    4

  3. COption (c)

    3

  4. DOption (d)

    2

View answer & explanation

Correct answer

Answer: (d)D.

2

Why this answer is correct

Given word: 'FRIENDLY'

After applying the specified transformations:

AlphabetsMAJORITY
Change Into- 1+ 1- 1+ 1- 1+ 1- 1- 1
Transformed AlphabetsLBIPQJSX

So, common letter is: I and J

Hence, the correct answer is "Option 4".

Question 75

Which of the following is/are NOT present in the plasma?

  1. AOption (a)

    Salts

  2. BOption (b)

    Proteins

  3. COption (c)

    Undigested food

  4. DOption (d)

    Hormones

View answer & explanation

Correct answer

Answer: (c)C.

Undigested food

Why this answer is correct

The Correct answer is Undigested food.

Key Points

  • Plasma is the liquid component of blood that holds the blood cells in whole blood in suspension.
  • It is composed mainly of water (about 90-92%) and contains various substances including salts, proteins, hormones, and waste products.
  • Salts in plasma help in maintaining osmotic balance, pH, and various other functions crucial for homeostasis.
  • Proteins in plasma include albumins, globulins, and fibrinogen, which play essential roles in maintaining osmotic balance, immune response, and blood clotting.
  • Hormones are also found in plasma and are vital for regulating physiological activities and maintaining homeostasis.
  • However, undigested food is not present in the plasma as it is usually processed and absorbed in the digestive system, and only nutrients absorbed from the food enter the bloodstream.

 Additional Information

  • Salts
  • Salts such as sodium, potassium, calcium, and magnesium are crucial for various cellular functions including nerve transmission and muscle contraction.
  • They help to maintain the osmotic balance and pH levels in the blood.
  • Proteins
  • Proteins in plasma serve multiple functions including transport, immune defense, and blood clotting.
  • Albumins maintain osmotic pressure, globulins are involved in the immune response, and fibrinogen is essential for the clotting process.
  • Hormones
  • Hormones are chemical messengers that regulate physiological processes including growth, metabolism, and reproductive functions.
  • They are secreted by various endocrine glands and transported via plasma to target organs.

Question 76

Use of regenerative cells in the process of budding is present in:

  1. AOption (a)

    Planaria

  2. BOption (b)

    Amoeba

  3. COption (c)

    Spirogyra

  4. DOption (d)

    Hydra

View answer & explanation

Correct answer

Answer: (d)D.

Hydra

Why this answer is correct

The correct answer is Hydra.

Key Points

  • Hydra is a genus of small, freshwater organisms of the phylum Cnidaria and class Hydrozoa.
  • Hydra reproduces asexually through a process known as budding.
  • In budding, a small bud develops on the body of the parent organism, grows by acquiring cells from the parent, and eventually detaches to form a new, genetically identical individual.
  • This process involves the use of regenerative cells, which allow Hydra to regenerate and form new buds.
  • Hydra's remarkable ability to regenerate is due to the presence of stem cells that can differentiate into any cell type needed for growth and repair.

 Additional Information

  • Planaria
  • Planaria are flatworms known for their ability to regenerate lost body parts, but they reproduce primarily through fission rather than budding.
  • They belong to the class Turbellaria in the phylum Platyhelminthes.
  • Amoeba
  • An Amoeba is a single-celled organism that primarily reproduces through a process called binary fission, not budding.
  • It belongs to the phylum Amoebozoa.
  • Spirogyra
  • Spirogyra is a filamentous green alga that reproduces through fragmentation and sexual reproduction, not budding.
  • It belongs to the class Zygnematophyceae in the phylum Chlorophyta.

Question 77

The atomic mass of carbon-12 isotope is:

  1. AOption (a)

    12 u

  2. BOption (b)

    14 u

  3. COption (c)

    6 u

  4. DOption (d)

    16 u

View answer & explanation

Correct answer

Answer: (a)A.

12 u

Why this answer is correct

The correct answer is 12 u.

Key Points

  • Carbon-12 is the most common isotope of carbon, consisting of 6 protons and 6 neutrons.
  • The atomic mass unit (u) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass).
  • The atomic mass of an atom is defined relative to the atomic mass of Carbon-12, which is set at 12 u.
  • This standardization helps in comparing the masses of different atoms.
  • The mass of Carbon-12 is exactly 12 u because it is the reference from which atomic masses are calculated.

 Additional Information

  • 14 u
  • This value is closer to the atomic mass of the isotope Carbon-14, which has 6 protons and 8 neutrons.
  • Carbon-14 is used in radiocarbon dating to determine the age of ancient objects.
  • 6 u
  • This is incorrect as it does not match the atomic mass of any naturally occurring carbon isotope.
  • 16 u
  • This value is closer to the atomic mass of the isotope Oxygen-16, which has 8 protons and 8 neutrons.
  • Oxygen-16 is the most abundant isotope of oxygen.

Question 78

Krishi Sakhi Convergence Programme (KSCP), under the Lakhpati Didi programme, was launched from which of the following places in June 2024 by Prime Minister Narendra Modi?

  1. AOption (a)

    Varanasi 

  2. BOption (b)

    Lucknow

  3. COption (c)

    Ahmedabad 

  4. DOption (d)

    Nagpur

View answer & explanation

Correct answer

Answer: (a)A.

Varanasi 

Why this answer is correct

The Correct answer is Varanasi.

Key Points

  • The Krishi Sakhi Convergence Programme (KSCP) is an initiative under the Lakhpati Didi programme.
  • This programme was launched by Prime Minister Narendra Modi in June 2024.
  • It was launched from the ancient city of Varanasi, which is also known for its rich cultural and historical heritage.
  • The aim of the KSCP is to empower rural women by providing them with skills and resources in agriculture and allied activities.
  • The programme seeks to improve the livelihood of rural women and make them lakhpatis (earning more than one lakh rupees annually).

 Additional Information

  • Lucknow
  • Lucknow is the capital city of the Indian state of Uttar Pradesh.
  • It is known for its rich history, culture, and heritage, including landmarks such as the Bara Imambara and Chota Imambara.
  • Lucknow is also famous for its unique style of Chikankari embroidery.
  • Ahmedabad
  • Ahmedabad is the largest city in the Indian state of Gujarat.
  • It is an important economic and industrial hub, known for its textile industry.
  • The city is home to the Sardar Vallabhbhai Patel International Airport and the Indian Institute of Management Ahmedabad (IIM-A).
  • Nagpur
  • Nagpur is a major city in the central part of India, located in the state of Maharashtra.
  • It is known as the Orange City due to its famous Nagpur oranges.
  • Nagpur is also the geographical center of India and houses the Zero Mile Stone.

Question 79

Which of the following equations is true, when two objects A and B of masses M and m are separated by a distance d, F is the force of attraction between them and G is the universal gravitational constant?

  1. AOption (a)

    F=GMd2\rm F=G\frac{M}{d^2}

  2. BOption (b)

    F=GM×md2\rm F=G\frac{M\times m}{d^2}

  3. COption (c)

    F=G1d2\rm F=G\frac{1}{d^2}

  4. DOption (d)

    F=GM×md\rm F=G\frac{M\times m}{d}

View answer & explanation

Correct answer

Answer: (b)B.

F=GM×md2\rm F=G\frac{M\times m}{d^2}

Why this answer is correct

The correct answer is F = G(M × m)/(d^2).

Key Points

  • The formula F = G(M × m)/(d^2) represents Newton's Law of Universal Gravitation.
  • According to this law, the force of attraction between two objects is directly proportional to the product of their masses (M and m).
  • The force is also inversely proportional to the square of the distance (d) between the two objects.
  • G is the universal gravitational constant, which has a value of approximately 6.674 × 10^-11 N(m/kg)^2.
  • This formula is crucial in understanding the gravitational interactions between objects, from small particles to astronomical bodies.

 Additional Information

  • Incorrect Options
  • F = G(M)/(d^2): This formula is incorrect because it does not include the mass of object B (m).
  • F = G(1)/(d^2): This formula is incorrect because it does not include the masses of either object.
  • F = G(M × m)/(d): This formula is incorrect because the force is inversely proportional to the square of the distance (d^2), not just the distance (d).
  • Important Points
  • Newton's Law of Universal Gravitation is fundamental in physics and astronomy.
  • This law helps in calculating the gravitational forces between celestial bodies, which is essential for understanding their orbits and movements.
  • The universal gravitational constant (G) was first measured by Henry Cavendish in 1798.

Question 80

A combination of two lenses of power +2.0 D and -0.25 D is equivalent to a single lens of power:

  1. AOption (a)

    +1.75 D

  2. BOption (b)

    +2.25 D

  3. COption (c)

    -3.5 D

  4. DOption (d)

    +1.25 D

View answer & explanation

Correct answer

Answer: (a)A.

+1.75 D

Why this answer is correct

The correct answer is +1.75 D.

Key Points

  • The power of a lens is measured in diopters (D).
  • The power of a combination of lenses is equal to the algebraic sum of the powers of the individual lenses.
  • Given lens powers: +2.0 D and -0.25 D.
  • To find the equivalent power, add the powers of the two lenses:
  • +2.0 D + (-0.25 D) = +1.75 D.
  • Thus, the combination of these two lenses is equivalent to a single lens of power +1.75 D.

 Additional Information

  • Lens Power
  • Diopter (D) is the unit of measurement for the optical power of a lens.
  • A lens with a power of +1 diopter brings parallel rays of light to focus at 1 meter.
  • The power of a lens is the reciprocal of its focal length in meters (P = 1/f).
  • Positive power indicates a converging lens, while negative power indicates a diverging lens.
  • Combination of Lenses
  • When lenses are combined, their individual powers add algebraically.
  • This is useful in optical instruments like microscopes and telescopes.
  • It is important to consider the sign of the power for accurate calculations.

Question 81

In a certain code language, 'ROSE' is coded as '4618' and 'SEAR' is coded as '6438'. What is the code for 'O' in the given code language?

  1. AOption (a)

    1

  2. BOption (b)

    6

  3. COption (c)

    4

  4. DOption (d)

    8

View answer & explanation

Correct answer

Answer: (a)A.

1

Why this answer is correct

Logic : No specific pattern is followed here, random digits are assigned to each letter.

So,

  • 'ROSE' is coded as '4618'
  • 'SEAR' is coded as '6438'

As some letters are common, so the codes will be :

LettersR / S / EOA
Codes4 / 6 / 813

​Therefore,

'O' is coded as '1'.

​Hence, "Option (1)" is the correct answer.

Question 82

A worker lifts a rice bag of 10 kg from the ground and puts it on the truck 2 m above the ground. Calculate the work done by him on the rice bag. (Given, g= 10 ms-2)

  1. AOption (a)

    100 J

  2. BOption (b)

    59 J

  3. COption (c)

    153 J

  4. DOption (d)

    200 J

View answer & explanation

Correct answer

Answer: (d)D.

200 J

Why this answer is correct

The correct answer is 200 J.

Key Points

  • To calculate the work done, we use the formula: Work Done (W) = Force (F) × Displacement (d).
  • The force exerted by the worker is equal to the weight of the rice bag, which is calculated by: Force (F) = Mass (m) × Acceleration due to gravity (g).
  • Here, the mass (m) of the rice bag is 10 kg.
  • The acceleration due to gravity (g) is given as 10 ms-2.
  • So, the force exerted is: F = 10 kg × 10 ms-2 = 100 N.
  • The displacement (d) of the rice bag is 2 meters (the height at which the bag is lifted).
  • Therefore, the work done by the worker is: W = F × d = 100 N × 2 m = 200 J.
  • Hence, the correct answer is 200 J.

 Additional Information

  • Work Done
  • In physics, work is defined as the amount of energy transferred by a force acting through a distance.
  • The unit of work is the joule (J), which is equivalent to one newton-meter.
  • Force
  • Force is a vector quantity that causes an object to accelerate. It is measured in newtons (N).
  • One newton is defined as the force required to accelerate a one-kilogram mass by one meter per second squared.
  • Acceleration due to Gravity
  • The acceleration due to gravity (g) on the surface of the Earth is approximately 9.8 ms-2, but it is often rounded to 10 ms-2 for simplicity in calculations.

Question 83

D, E, F, G, L, M and N are sitting around a circular table facing the centre. Only two people sit between M and N when counted from the right of M. Only two people sit between N and E when counted from the right of N. Only three people sit between M and F when counted from the right of M. D sits to the immediate left of G. Who sits third to the left of L?

  1. AOption (a)

    D

  2. BOption (b)

    M

  3. COption (c)

    G

  4. DOption (d)

    N

View answer & explanation

Correct answer

Answer: (c)C.

G

Why this answer is correct

Given:

D, E, F, G, L, M and N are sitting around a circular table facing the centre.

Only two people sit between M and N when counted from the right of M.

Only two people sit between N and E when counted from the right of N.

Only three people sit between M and F when counted from the right of M.

D sits to the immediate left of G.

So, 'G' sits third to the left of L.

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

Question 84

Read the given statements and conclusions carefully. You have to take the given statements to be true even if they seem to be at variance from commonly known facts and decide which conclusion(s) logically follow(s) from the given statements.

Statements:

Some books are trees.

All trees are mats.

All mats are ponds.

Conclusions:

(I) Some ponds are books.

(II) Some mats are books.

  1. AOption (a)

    Only conclusion (II) follows.

  2. BOption (b)

    Neither conclusion (I) nor (II) follows.

  3. COption (c)

    Only conclusion (I) follows.

  4. DOption (d)

    Both conclusions (I) and (II) follow.

View answer & explanation

Correct answer

Answer: (d)D.

Both conclusions (I) and (II) follow.

Why this answer is correct

The least possible Venn diagram:

Conclusion:

I. Some ponds are books → True (because some books are trees and all trees are ponds)

II. Some mats are books → True (because some books are trees and all trees are mats)

So, Both conclusions (I) and (II) follow.

Hence, the correct answer is "Option 4".

Question 85

Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which pair does not belong to that group?

(Note: The odd one out is not based on the number of consonants/vowels or their position in the letter-cluster.)

  1. AOption (a)

    AW-VP

  2. BOption (b)

    KO-WA

  3. COption (c)

    BX-WQ

  4. DOption (d)

    TP-OI

View answer & explanation

Correct answer

Answer: (b)B.

KO-WA

Why this answer is correct

The logic followed here is:

Option 1) AW-VP

Option 2) KO-WA

Option 3) BX-WQ

Option 4) TP-OI

Thus, out of all the options 'KO-WA' is the odd one out.

Hence, "Option 2" is the correct answer

Question 86

The age of a mother six years ago was six times the age of her daughter, at that time. Three years hence, the mother will be thrice as old as her daughter. What is the difference between the present age of the mother and her daughter?

  1. AOption (a)

    24 years

  2. BOption (b)

    42 years

  3. COption (c)

    36 years

  4. DOption (d)

    30 years

View answer & explanation

Correct answer

Answer: (d)D.

30 years

Why this answer is correct

Shortcut Trick

Ratio 6 years ago (M:D) = 6 : 1 (Difference = 5 units)

Ratio 3 years hence (M:D) = 3 : 1 = 6 : 2 (Difference = 4 units)

Equating differences: Ratio1 × 4 → 24 : 4 | Ratio2 × 5 → 30 : 10

Change in units = 30 − 24 = 6 units → Total years gap = 6 + 3 = 9 years

1 unit = 9/6 = 1.5 years | Age difference = 20 units × 1.5 = 30 years

∴ The correct answer is 30 years.

Alternate Method

Let daughter age 6 years ago be x and mother age be 6x.

Present ages: Daughter = x + 6, Mother = 6x + 6

Ages 3 years hence: Daughter = x + 9, Mother = 6x + 9

⇒ 6x + 9 = 3 × (x + 9)

⇒ 6x + 9 = 3x + 27

⇒ 3x = 18

⇒ x = 6

⇒ Mother age 6 yrs ago = 6 × 6 = 36; Daughter age 6 yrs ago = 6

⇒ Age difference = 36 − 6 = 30 years

∴ The correct answer is 30 years.

Additional Information

Constant Difference Property

The age difference between two individuals always remains constant throughout their lives, regardless of the number of years passed.

Ratio Balancing

To solve age problems using ratios, multiply the ratios such that the numerical difference between the ratio parts of the two people becomes equal in both time periods.

Question 87

Which one of the following plant parts is NOT used for vegetative propagation?

  1. AOption (a)

    Seed 

  2. BOption (b)

    Stem 

  3. COption (c)

    Leaves 

  4. DOption (d)

    Root 

View answer & explanation

Correct answer

Answer: (a)A.

Seed 

Why this answer is correct

The Correct answer is Seed.

Key Points

  • Vegetative propagation involves the use of parts of a plant other than seeds to reproduce new plants.
  • Seeds are used in sexual reproduction, not vegetative propagation.
  • Common plant parts used in vegetative propagation include stems, leaves, and roots.
  • Stem cuttings from plants like roses and hibiscus can be used to grow new plants.
  • Certain plants like succulents can propagate from their leaves.
  • Root tubers such as those from sweet potatoes can also be used for vegetative propagation.

 Additional Information

  • Stem
  • Stem cuttings are a popular method of vegetative propagation.
  • Examples include plants like roses, hibiscus, and sugarcane.
  • Leaves
  • Certain plants like succulents can propagate from their leaves.
  • Examples include jade plant and kalanchoe.
  • Root
  • Root tubers such as sweet potatoes and taproots like carrots can be used for vegetative propagation.

Question 88

Which of the following is/are NOT a parasitic organism? 

  1. AOption (a)

    Ticks 

  2. BOption (b)

    Cuscuta 

  3. COption (c)

    Amoeba  

  4. DOption (d)

    Lice  

View answer & explanation

Correct answer

Answer: (c)C.

Amoeba  

Why this answer is correct

The correct answer is Amoeba.

Key Points

  • An Amoeba is a type of single-celled organism found in various water bodies.
  • Amoebas belong to the phylum Amoebozoa.
  • They are typically free-living and do not rely on a host for survival.
  • Amoebas move and ingest food through a process called phagocytosis, using extensions of their cell membrane known as pseudopodia.
  • Unlike parasitic organisms, amoebas do not exhibit a parasitic relationship where they harm a host organism to derive nutrients.

 Additional Information

  • Ticks
  • Ticks are small arachnids that are ectoparasites, meaning they live on the outside of their host.
  • They feed on the blood of mammals, birds, and sometimes reptiles and amphibians.
  • Ticks can transmit various diseases to humans and animals, including Lyme disease.
  • Cuscuta
  • Cuscuta, also known as dodder, is a genus of parasitic plants.
  • These plants have no chlorophyll and rely on host plants for nutrients.
  • Cuscuta wraps around host plants and forms haustoria to absorb nutrients directly from them.
  • Lice
  • Lice are small, wingless insects that are parasitic on mammals and birds.
  • They live in the hair or feathers of their hosts and feed on blood or skin.
  • Lice infestations can cause itching and discomfort and are often spread through close contact.

Question 89

In a certain code language, 'PILED' is coded as '65428' and 'PEDAL' is coded as '57628'. What is the code for 'I' in the given code language?

  1. AOption (a)

    6

  2. BOption (b)

    2

  3. COption (c)

    4

  4. DOption (d)

    8

View answer & explanation

Correct answer

Answer: (c)C.

4

Why this answer is correct

Logic : No specific pattern is followed here, random digits are assigned to each letter.

So,

  • 'PILED' is coded as '65428'
  • 'PEDAL' is coded as '57628'

As some letters are common, so the codes will be :

LettersP / L / E / DIA
Codes6 / 5 / 2 / 847

​Therefore,

'I' is coded as '4'.

​Hence, "Option (3)" is the correct answer.

Question 90

Which of the following options should come in place of the question mark (?) in the given series based on the English alphabetical order?

YTL, QLD, IDV, AVN,?

  1. AOption (a)

    SMF

  2. BOption (b)

    SMG

  3. COption (c)

    SNG

  4. DOption (d)

    SNF

View answer & explanation

Correct answer

Answer: (d)D.

SNF

Why this answer is correct

The logic followed here is:

Hence, "Option 4" is the correct answer.

Question 91

In a row of 45 students, facing north, Kevin is 16th from the right end. If Luther is 10th to the left of Kevin, what is Luther's position from the left end of the row?

  1. AOption (a)

    22nd

  2. BOption (b)

    23rd

  3. COption (c)

    20th

  4. DOption (d)

    21st

View answer & explanation

Correct answer

Answer: (c)C.

20th

Why this answer is correct

The logic followed here is:

Position of Kevin from the right = 16th

Since there are 45 students in total, Kevin's position from the left end can be calculated as:

Position of Kevin from the left = (Total students - Position from the right + 1)

= 45 - 16 + 1

= 30th

Luther is 10th to the left of Kevin.

So, Luther's position from the left = Position of Kevin from the left - 10

= 30 - 10

= 20th

Hence, the correct answer is "Option 3".

Question 92

Which of the following options should come in place of the question mark (?) in the given series based on the English alphabetical order?

RMK, UOL, XQM, ASN,?

  1. AOption (a)

    DUP

  2. BOption (b)

    DUO

  3. COption (c)

    EUO

  4. DOption (d)

    DQO

View answer & explanation

Correct answer

Answer: (b)B.

DUO

Why this answer is correct

The logic followed here is:

Hence, "Option 2" is the correct answer.

Question 93

One year ago, the ratio of the ages of Sara and Dipti was 3 : 4, respectively. Four years hence, this ratio would become 4 : 5. The present age of Sara is:

  1. AOption (a)

    12 years

  2. BOption (b)

    19 years

  3. COption (c)

    15 years

  4. DOption (d)

    16 years

View answer & explanation

Correct answer

Answer: (d)D.

16 years

Why this answer is correct

Shortcut Trick

Ratio 1 year ago (Sara : Dipti) = 3 : 4

Ratio 4 years hence (Sara : Dipti) = 4 : 5

Difference in ratio parts (4−3) and (5−4) = 1 unit

Total time gap = 1 + 4 = 5 years ⇒ 1 unit = 5 years

Sara age 1 year ago = 3 × 5 = 15 years

Sara present age = 15 + 1 = 16 years

∴ The correct answer is 16 years.

Alternate Method

Given: Ratio of Sara and Dipti age 1 year ago = 3 : 4

Let their ages 1 year ago be 3x and 4x respectively.

⇒ Present age of Sara = 3x + 1

⇒ Present age of Dipti = 4x + 1

⇒ Ages after 4 years: Sara = (3x + 1) + 4 = 3x + 5; Dipti = (4x + 1) + 4 = 4x + 5

⇒ According to question: (3x + 5) / (4x + 5) = 4 / 5

⇒ 5(3x + 5) = 4(4x + 5)

⇒ 15x + 25 = 16x + 20

⇒ x = 5

⇒ Sara present age = 3(5) + 1 = 16 years

∴ The correct answer is 16 years.

Additional Information

Ratio Difference Concept

If the age difference between two people is constant, the difference between their ratio parts must also be made equal across different time periods.

Cross Multiplication Method

For equations in the form (ax + b)/(cx + d) = m/n, use cross multiplication to solve for the variable x quickly.

Age Problems Logic

If 'n' years ago age was A, then Present Age = A + n. If 'm' years hence age will be B, then Present Age = B − m.

Question 94

If tan θ + cot θ = 13, then find the value of 8 tan2 θ + 8 cot2 θ.

  1. AOption (a)

    167

  2. BOption (b)

    1336

  3. COption (c)

    1372

  4. DOption (d)

    169

View answer & explanation

Correct answer

Answer: (b)B.

1336

Why this answer is correct

Shortcut Trick

Given: tan θ + cot θ = 13

Using the algebraic identity: if x + 1/x = k, then x2 + 1/x2 = k2 − 2

Since cot θ = 1/tan θ, we have tan2 θ + cot2 θ = 132 − 2 = 169 − 2 = 167

Required value = 8 × (tan2 θ + cot2 θ) = 8 × 167

∴ The correct answer is 1336.

Alternate Method

Given: tan θ + cot θ = 13

Formula Used: (a + b)2 = a2 + b2 + 2ab

⇒ (tan θ + cot θ)2 = 132

⇒ tan2 θ + cot2 θ + 2 × tan θ × cot θ = 169

⇒ Since tan θ × cot θ = 1, we get tan2 θ + cot2 θ + 2 = 169

⇒ tan2 θ + cot2 θ = 169 − 2 = 167

⇒ Now, multiply the entire expression by 8:

⇒ 8 × (tan2 θ + cot2 θ) = 8 × 167

⇒ 8 tan2 θ + 8 cot2 θ = 1336

∴ The correct answer is 1336.

Additional Information

Reciprocal Identities

The product of tan θ and cot θ is always 1 because they are reciprocals of each other (cot θ = 1/tan θ).

Algebraic Squared Relation

For any variable and its reciprocal x + 1/x = a, the value of x2 + 1/x2 is always calculated as a2 − 2.

Trigonometric Squares

Standard identities include 1 + tan2 θ = sec2 θ and 1 + cot2 θ = cosec2 θ, which are useful for complex conversions.

Question 95

What is the position of the image formed by a concave mirror if the object is placed just beyond the centre of curvature of the mirror?

  1. AOption (a)

    At the focus

  2. BOption (b)

    At infinity

  3. COption (c)

    At the centre of curvature

  4. DOption (d)

    Between the centre of curvature and the focus point

View answer & explanation

Correct answer

Answer: (d)D.

Between the centre of curvature and the focus point

Why this answer is correct

The Correct answer is Between the centre of curvature and the focus point.

Key Points

  • When an object is placed just beyond the centre of curvature of a concave mirror, the image is formed between the centre of curvature and the focus point.
  • The image formed is real, inverted, and reduced in size compared to the object.
  • This is due to the properties of concave mirrors, where light rays that are parallel to the principal axis converge at the focus after reflection.
  • The position of the image can be determined using the mirror equation: 1/f = 1/v + 1/u, where f is the focal length, v is the image distance, and u is the object distance.
  • In this case, since the object is placed beyond the centre of curvature (i.e., at a distance greater than twice the focal length), the resulting image is found between the centre of curvature and the focus.

 Additional Information

  • At the focus
  • If the object is placed at infinity (i.e., a very large distance from the mirror), the image formed by a concave mirror will be at the focus.
  • At infinity
  • If the object is placed at the focus of a concave mirror, the reflected rays are parallel and the image is formed at infinity.
  • At the centre of curvature
  • If the object is placed at the centre of curvature of a concave mirror, the image is formed at the centre of curvature, and it is real, inverted, and of the same size as the object.

Question 96

Read the given statements and conclusions carefully. You have to take the given statements to be true even if they seem to be at variance from commonly known facts and decide which conclusion(s) logically follow(s) from the given statements.

Statements:

Some slippers are shoes.

Some shoes are belts.

Conclusions:

(I) Some belts are slippers.

(II) No belt is a slipper.

  1. AOption (a)

    Only conclusion (I) follows

  2. BOption (b)

    Neither conclusion (I) nor (II) follows

  3. COption (c)

    Only conclusion (II) follows

  4. DOption (d)

    Both conclusions (I) and (II) follow

View answer & explanation

Correct answer

Answer: (b)B.

Neither conclusion (I) nor (II) follows

Why this answer is correct

The least possible Venn diagram:

Conclusions:

I. Some belts are slippers → False (because no direct relationship is given between belts and slipers so it may be possible but not defined)

II. No belt is a slipper → False (because no direct relationship is given between belts and slipers so it may be possible but not defined)

So, Neither conclusion (I) nor (II) follows.

Hence, the correct answer is "Option 2".

Question 97

A change of state directly from gas to solid without changing into liquid state is called:

  1. AOption (a)

    fusion

  2. BOption (b)

    solidification 

  3. COption (c)

    vaporisation

  4. DOption (d)

    deposition

View answer & explanation

Correct answer

Answer: (d)D.

deposition

Why this answer is correct

The Correct answer is deposition.

Key Points

  • The process of changing directly from a gas to a solid without passing through the liquid state is known as deposition.
  • This phase transition is the reverse of sublimation, which is the transition from a solid to a gas.
  • An example of deposition is the formation of frost on cold surfaces from water vapor in the air.
  • In physical chemistry and material science, deposition is a process used to create thin films or coatings on surfaces.
  • Deposition is utilized in manufacturing processes such as chemical vapor deposition (CVD) and physical vapor deposition (PVD).

 Additional Information

  • Fusion
  • Fusion is the process of changing from a solid to a liquid state.
  • It is commonly referred to as melting.
  • Examples include ice melting into water.
  • Solidification
  • Solidification is the process of changing from a liquid to a solid state.
  • This process is also known as freezing.
  • Examples include water freezing into ice.
  • Vaporisation
  • Vaporisation is the process of changing from a liquid to a gas state.
  • This can occur through evaporation (at the surface) or boiling (throughout the liquid).
  • Examples include water boiling into steam.

Question 98

Which team won the gold medal at 2024 Badminton Asia Team Championships in February 2024?

  1. AOption (a)

    Thailand

  2. BOption (b)

    Japan

  3. COption (c)

    Malaysia

  4. DOption (d)

    India

View answer & explanation

Correct answer

Answer: (d)D.

India

Why this answer is correct

The correct answer is India.

Key Points

  • India won the gold medal at the 2024 Badminton Asia Team Championships held in February 2024.
  • This achievement marked a significant milestone for Indian badminton on the Asian stage.
  • India's team showcased exceptional performance, defeating other strong contenders from Asia.
  • The Badminton Asia Team Championships is a prestigious tournament that brings together the best teams from across the continent.
  • Winning this championship reflects the hard work and dedication of the Indian players and coaching staff.
  • It also highlights the rising stature of India in the international badminton arena.

 Additional Information

  • Thailand
  • Thailand has a strong badminton tradition and has produced several world-class players.
  • Thailand's players frequently perform well in international tournaments, making them a formidable opponent.
  • Japan
  • Japan is known for its disciplined and strategic approach to badminton.
  • Japanese players have achieved significant success in both men's and women's events on the global stage.
  • Malaysia
  • Malaysia has a rich history in badminton, with several legends like Lee Chong Wei hailing from the country.
  • Malaysia consistently fields strong teams in international competitions.

Question 99

On November 9, 2024, which city recorded the highest Air Quality Index (AQI) among Punjab, Haryana, and Chandigarh? 

  1. AOption (a)

    Bahadurgarh 

  2. BOption (b)

    Sonipat

  3. COption (c)

    Mandi Gobindgarh

  4. DOption (d)

    Chandigarh

View answer & explanation

Correct answer

Answer: (d)D.

Chandigarh

Why this answer is correct

The correct answer is Chandigarh.

Key Points

  • The Air Quality Index (AQI) is a measure used to communicate how polluted the air currently is or how polluted it is forecast to become.
  • Chandigarh, being a union territory and capital of two states (Punjab and Haryana), often faces significant air quality issues due to industrial activities, vehicular emissions, and seasonal crop burning in neighboring states.
  • On November 9, 2024, Chandigarh recorded the highest AQI among the regions of Punjab, Haryana, and Chandigarh, indicating severe air pollution.
  • High AQI levels in Chandigarh can be attributed to urbanization, high vehicular density, and proximity to industrial regions.
  • Efforts are being made to control pollution levels through government initiatives and public awareness campaigns.

 Additional Information

  • Bahadurgarh
  • Bahadurgarh is a city located in the state of Haryana.
  • It is part of the National Capital Region (NCR) and is known for its proximity to Delhi.
  • While it has industrial areas, its pollution levels are generally lower compared to major cities like Chandigarh.
  • Sonipat
  • Sonipat is another city in Haryana, located close to Delhi.
  • It has a mix of residential and industrial areas, but its AQI levels are typically not as high as Chandigarh on the given date.
  • Mandi Gobindgarh
  • Mandi Gobindgarh is a town in the state of Punjab.
  • It is known for its steel production and industrial activities.
  • Despite its industrial nature, it did not record the highest AQI compared to Chandigarh on November 9, 2024.

Question 100

A girl pushes a trolley with a constant force F through a distance s, the work done will be:

  1. AOption (a)

    F × s

  2. BOption (b)

    F + s

  3. COption (c)

    F/s

  4. DOption (d)

    F - s

View answer & explanation

Correct answer

Answer: (a)A.

F × s

Why this answer is correct

The Correct answer is F × s

Key Points

  • The formula for work done is: W = F × s, where W is the work done, F is the constant force applied, and s is the distance through which the force is applied.
  • In this scenario, the girl pushes the trolley with a constant force of F over a distance s. The work done is the product of the force applied and the distance moved in the direction of the force.
  • Work is a scalar quantity, and its unit in the SI system is Joule (J), where 1 Joule = 1 Newton meter (N·m). The formula reflects this relationship.

100 questions in the full paper