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NDA 2026 Previous Year GK Questions with Answers

GK questions asked in NDA 2026, with answers and explanations.

Previous Year Questions

Q1.General ScienceAsked in: NDA · NDA-I 2026, GATMedium

A particle is moved from point X to point Y under a force field. The work done depends only on the initial and final speeds. Which one of the following is correct?

  1. A.The force is conservative.
  2. B.The net work equals the change in kinetic energy.
  3. C.The force is constant.
  4. D.The velocity must always increase.
Show answer
Correct answer: B. The net work equals the change in kinetic energy.

A work done that is fixed by the starting and ending speeds alone is exactly what the work-energy theorem states: W(net) = ½mv² − ½mu².

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Q2.General ScienceAsked in: NDA · NDA-II 2026, GATHard

Two conducting wires made of the same material have lengths L and 1.2 L. If the volume of the longer wire is half that of the shorter wire, then what is the electric resistance of the longer wire in comparison with the shorter wire?

  1. A.288% larger
  2. B.200% larger
  3. C.188% larger
  4. D.108% larger
Show answer
Correct answer: C. 188% larger

The longer wire's resistance works out to 2.88 times that of the shorter one, which is 188% more. Resistance is R = ρL/A, where ρ is the resistivity of the material.

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Q3.General ScienceAsked in: NDA · NDA-I 2026, GATHard

An object is placed far beyond the centre of curvature of a concave mirror. The object then starts accelerating towards the mirror. Which one of the following is correct?

  1. A.The image will accelerate towards the centre of curvature.
  2. B.The image will accelerate towards the focus.
  3. C.The image will accelerate towards the pole of the mirror.
  4. D.The image will move with a constant speed towards the focus.
Show answer
Correct answer: A. The image will accelerate towards the centre of curvature.

As an object comes in from far away towards C, its real, inverted image moves out from the focus towards C, and the two meet at C. For a concave mirror, an object at infinity forms its image at the focus F, and an object at the centre of curvature…

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Q5.General ScienceAsked in: NDA · NDA-I 2026, GATEasy

A person jumps from a height on soft sand. Which one of the following is the correct reason for less likely injury to the person?

  1. A.The sand exerts no reaction force.
  2. B.The sand reduces the change in momentum.
  3. C.The sand increases the impact time.
  4. D.The sand increases the momentum.
Show answer
Correct answer: C. The sand increases the impact time.

Soft sand gives way slowly, so the person is brought to rest over a longer time and the force on the body is smaller.

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Q7.General ScienceAsked in: NDA · NDA-I 2026, GATHard

A floating body is in stable state. Which one of the following is correct?

  1. A.The centre of gravity of the body is above its centre of buoyancy.
  2. B.The centre of gravity of the body is below its centre of buoyancy.
  3. C.The centre of gravity of the body coincides with its centre of buoyancy.
  4. D.The centre of gravity of the body is below the metacentre.
Show answer
Correct answer: D. The centre of gravity of the body is below the metacentre.

A floating body is stable only when its metacentre lies above its centre of gravity. When a floating body tilts slightly, its centre of buoyancy, the centre of the displaced liquid, shifts to one side.

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Q8.General ScienceAsked in: NDA · NDA-I 2026, GATMedium

For an object in gravitational field, the gravitational potential is the same at two points A and B, but the gravitational field is not the same at these two points. Which one of the following statements is correct?

  1. A.Positive work is done by gravity in moving the object from point A to point B.
  2. B.Negative work is done by gravity in moving the object from point A to point B.
  3. C.Gravity must be non-conservative in such a region.
  4. D.No work is done by gravity in moving the object from point A to point B.
Show answer
Correct answer: D. No work is done by gravity in moving the object from point A to point B.

Work done by gravity depends only on the difference in potential between the two points, and here that difference is zero.

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Q9.General ScienceAsked in: NDA · NDA-II 2026, GATHard

Consider the following : I. Gravitational field due to a spherical body II. Electrostatic field due to a point charge III. Strong nuclear force field due to a proton IV. Magnetic field due to a bar magnet How many of the above follow the inverse square law ?

  1. A.One
  2. B.Two
  3. C.Three
  4. D.All four
Show answer
Correct answer: B. Two

Only the gravitational field of a spherical body and the electrostatic field of a point charge fall off as 1/r².

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Q10.General ScienceAsked in: NDA · NDA-I 2026, GATHard

For an ideal gas, a process is described by P = kT, where k is a constant. If the molar heat capacity for this process is C, then which one of the following is correct (where the symbols have their usual meanings)?

  1. A.C = Cp
  2. B.C = Cv
  3. C.C = (Cp + Cv)/2
  4. D.C is never constant
Show answer
Correct answer: B. C = Cv

If pressure is proportional to temperature for a fixed amount of ideal gas, the volume must stay constant, so the process is isochoric.

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Q11.General ScienceAsked in: NDA · NDA-II 2026, GATHard

Consider the following statements:

I. The weight of an object is the same everywhere on the surface of the Earth, but its inertial mass could be different.

II. The inertial mass and gravitational mass of an object are proportional and the proportionality constant is the same everywhere.

III. The inertial mass and weight of an object are the same at different places on Earth.

Which of the statements given above is/are correct?

  1. A.I only
  2. B.II only
  3. C.I and II
  4. D.II and III
Show answer
Correct answer: B. II only

Mass is the same everywhere, but weight changes with g, so only statement II holds. Inertial mass measures how much a body resists a change in motion (F = ma); gravitational mass measures how strongly gravity pulls it.

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Q12.General ScienceAsked in: NDA · NDA-II 2026, GATMedium

A tennis ball of mass 350 g is thrown vertically upwards at a speed of 4 m/s. If M is the maximum gravitational potential energy of the ball and H is the maximum height it reaches, then which one of the following is correct? (Take g = 10 m/s²)

  1. A.M = 5·6 J, H = 1·6 m
  2. B.M = 2·8 J, H = 1·6 m
  3. C.M = 5·6 J, H = 0·8 m
  4. D.M = 2·8 J, H = 0·8 m
Show answer
Correct answer: D. M = 2·8 J, H = 0·8 m

At the top of its flight all the kinetic energy of the ball has turned into gravitational potential energy. The mass is 350 g, that is 0·35 kg.

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Q13.General ScienceAsked in: NDA · NDA-I 2026, GATMedium

Two forces of equal magnitude simultaneously act at a point. It is observed that the resultant force is equal in magnitude to the individual forces. Which of the following statements is/are correct? I. The angle between one of the individual forces and the resultant force is π/3. II. The angle between the individual forces is 2π/3. Select the answer using the code given below.

  1. A.I only
  2. B.II only
  3. C.Both I and II
  4. D.Neither I nor II
Show answer
Correct answer: C. Both I and II

Two equal forces give a resultant of the same size only when they are 120° apart, and the resultant then makes 60° with each.

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Q14.General ScienceAsked in: NDA · NDA-II 2026, GATEasy

The bob of a simple pendulum is displaced from its mean position and then released from rest 0.20 m above its mean position. What is the speed of the bob as it passes through the mean position? (Take g = 10 m/s²)

  1. A.0 m/s
  2. B.1 m/s
  3. C.2 m/s
  4. D.√10 m/s
Show answer
Correct answer: C. 2 m/s

All the potential energy at the top turns into kinetic energy at the mean position, so v = √(2gh) = √(2 × 10 × 0.20) = 2 m/s. When the bob is released from rest at height h, it has potential energy mgh and no kinetic energy.

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Q15.General ScienceAsked in: NDA · NDA-I 2026, GATHard

A pendulum of length L oscillates with an angular amplitude of θ = 60° and time period T. Let T₀ = 2π√(L/g) be the time period for small angle of oscillations, where g is the acceleration due to gravity. If air resistance is negligibly small and the string remains straight, then which one of the following is correct?

  1. A.T will be slightly greater than T₀.
  2. B.T will be slightly smaller than T₀.
  3. C.T will be exactly equal to T₀.
  4. D.T will depend upon the mass of the bob.
Show answer
Correct answer: A. T will be slightly greater than T₀.

The formula T₀ = 2π√(L/g) holds only for small swings; at large amplitudes the period grows.

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Q16.General ScienceAsked in: NDA · NDA-II 2026, GATMedium

A bicycle racing track is a level circular road of radius 10 m. Three cyclists P, Q and R with identical cycles are cycling on the track with speeds 2 m/s, 3 m/s and 5 m/s respectively. If the coefficient of friction between the tyres and the road is 0.1, then which cyclist will slip? (Take g = 10 m/s²)

  1. A.P only
  2. B.Q only
  3. C.R only
  4. D.All will slip
Show answer
Correct answer: C. R only

On a level curve, friction alone supplies the centripetal force, so a cyclist slips when the needed force exceeds the maximum friction.

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All Defence previous year questions