Skip to content
GK24
Prime
General ScienceMediumAsked in: NDA · NDA-II 2017, GAT

An object moves in a circular path with a constant speed. Which one of the following statements is correct ?

  1. A.The centripetal acceleration of the object is smaller for a gentle curve (i.e., curve of larger radius) than that for a sharp curve (i.e., curve of smaller radius).
  2. B.The centripetal acceleration is greater for a gentle curve than that for a sharp curve.
  3. C.The centripetal acceleration is the same for both, the gentle and sharp curves.
  4. D.The centripetal acceleration causes the object to slow down.

Correct answer

A. The centripetal acceleration of the object is smaller for a gentle curve (i.e., curve of larger radius) than that for a sharp curve (i.e., curve of smaller radius).

Explanation

The correct answer is A: the centripetal acceleration is smaller on a gentle curve than on a sharp curve. At a fixed speed v, centripetal acceleration equals v²/r, so a larger radius gives a smaller acceleration.

An object moving in a circle at constant speed is still accelerating, because its direction keeps changing. This acceleration always points towards the centre of the circle and has the size v²/r. If the speed stays the same, doubling the radius halves the acceleration, and halving the radius doubles it. That is why a car can take a gentle bend safely at a speed that would make it skid on a sharp bend, where it needs a much larger inward force from friction.

B is wrong because it reverses the relation; a larger radius means a smaller acceleration, not a greater one.

C is wrong because the acceleration depends on the radius, so it cannot be the same for both curves.

D is wrong because centripetal acceleration is perpendicular to the motion; it changes only the direction, not the speed.

Exam tip: centripetal acceleration = v²/r, directed towards the centre; it changes direction, never speed.

Practice Questions

View all
Q1.General ScienceAsked in: UPSC CAPF · CAPF 2025, Paper IMedium

Which one among the following statements is not correct?

  1. A.The reaction of methane and chlorine in sunlight produces hydrogen gas.
  2. B.Palladium catalyzes the addition of hydrogen gas on an alkene.
  3. C.Ethanol burns in oxygen to give carbon dioxide, water and releases heat and light.
  4. D.Unsaturated hydrocarbons burn with a sooty flame.
Show answer
Correct answer: A. The reaction of methane and chlorine in sunlight produces hydrogen gas.

Methane and chlorine react in sunlight to give chloromethane and hydrogen chloride, not hydrogen gas. This is a substitution reaction: CH4 + Cl2 → CH3Cl + HCl in the presence of sunlight.

Q2.General ScienceAsked in: UPSC CAPF · CAPF 2025, Paper IMedium

Which of the following statements relating to carbon and its compounds are correct? 1. 1-Propyne has three double bonds. 2. The boiling point of acetic acid is higher than methane. 3. Ethanol reacts with sodium metal and produces hydrogen gas. 4. Esters give effervescence on reaction with sodium bicarbonate. Select the answer using the code given below.

  1. A.1 and 3
  2. B.2 and 3 only
  3. C.1 and 2
  4. D.2, 3 and 4
Show answer
Correct answer: B. 2 and 3 only

Acetic acid boils far above methane, and ethanol gives hydrogen with sodium, while statements 1 and 4 are false. Propyne (CH3–C≡CH) is an alkyne: it has one carbon–carbon triple bond and no double bonds, so statement 1 is wrong.

Q3.General ScienceAsked in: UPSC CAPF · CAPF 2025, Paper IMedium

Which one among the following statements regarding gypsum is not correct?

  1. A.On heating gypsum at 373 K, it loses water molecules and becomes CaSO4 · H2O.
  2. B.On mixing with water, plaster of Paris changes to gypsum.
  3. C.Plaster of Paris is used for supporting fractured bones.
  4. D.Although gypsum possesses water of crystallization, it is not a liquid at room temperature.
Show answer
Correct answer: A. On heating gypsum at 373 K, it loses water molecules and becomes CaSO4 · H2O.

Gypsum heated at 373 K becomes calcium sulphate hemihydrate, CaSO4 · ½H2O, which is plaster of Paris, not CaSO4 · H2O as the statement says.

Q4.General ScienceAsked in: UPSC CAPF · CAPF 2026, Paper IEasy

Which of the following is/are the basic step(s) in genetically modifying an organism? 1. Identification of DNA with desirable genes 2. Introduction of the identified DNA into the host 3. Maintenance of introduced DNA in the host and transfer of the DNA to its progeny Select the correct answer using the code given below.

  1. A.1 only
  2. B.1, 2 and 3
  3. C.2 and 3 only
  4. D.3 only
Show answer
Correct answer: B. 1, 2 and 3

Making a genetically modified organism needs all three steps: find the useful DNA, put it into the host, and make sure the host keeps it and passes it on.

Q5.General ScienceAsked in: NDA · NDA-II 2018, GATMedium

If one set of chromosomes for a given plant is represented as N; in case of double fertilization, the zygote and the endosperm nucleus of a diploid plant would have how many sets of chromosomes respectively?

  1. A.N and 2N
  2. B.2N and 2N
  3. C.N and 3N
  4. D.2N and 3N
Show answer
Correct answer: D. 2N and 3N

The zygote is diploid (2N) and the primary endosperm nucleus is triploid (3N). Double fertilisation is a feature of flowering plants.