Physics · NDA previous year questions

2026 45 questions

1. Q512026 · 13 Sept 2026

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

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

   Answer: C

2. Q522026 · 13 Sept 2026

   The bob of a simple pendulum is displaced from its mean position and then released from rest $0.20\mathrm{m}$ above its mean position. What is the speed of the bob as it passes through the mean position? (Take $g=10m/{\mathrm{s}}^2$)

   1. A.$0m/s$
   2. B.$1m/s$
   3. C.$2m/s$
   4. D.$\sqrt{10}m/s$
   Show answer

   Answer: C

3. Q532026 · 13 Sept 2026

   A tennis ball of mass $350\mathrm{g}$ is thrown vertically upwards at a speed of $4m/s$. 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 $g=10m/{\mathrm{s}}^2$)

   1. A.$M=5.6\mathrm{J}$, $H=1.6\mathrm{m}$
   2. B.$M=2.8\mathrm{J}$, $H=1.6\mathrm{m}$
   3. C.$M=5.6\mathrm{J}$, $H=0.8\mathrm{m}$
   4. D.$M=2.8\mathrm{J}$, $H=0.8\mathrm{m}$
   Show answer

   Answer: D

4. Q542026 · 13 Sept 2026

   Which of the following is correct regarding the total internal reflection at the interface between two different optical media?

   1. A.The phenomenon of total internal reflection can occur only if light is passing at any angle from a medium of low refractive index to a medium of high refractive index.
   2. B.The phenomenon of total internal reflection can occur only if light is passing from a medium of high refractive index to a medium of low refractive index and at an angle greater than the critical angle.
   3. C.The phenomenon of total internal reflection can occur only if light is passing at any angle from a medium of high refractive index to a medium of low refractive index.
   4. D.The phenomenon of total internal reflection can occur only if light is passing from a medium of low refractive index to a medium of high refractive index and at an angle greater than the critical angle.
   Show answer

   Answer: B

5. Q552026 · 13 Sept 2026

   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

   Answer: B

6. Q562026 · 13 Sept 2026

   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

   Answer: C

7. Q592026 · 13 Sept 2026
   
   1. A.$v=\sqrt{\frac{2F_{0}L}{m}}$
   2. B.$v=\sqrt{\frac{F_{0}L}{m}}$
   3. C.$v=\sqrt{\frac{F_{0}L}{2m}}$
   4. D.$v=0$
   Show answer

   Answer: B

8. Q602026 · 13 Sept 2026

   A narrow tunnel passes through the centre of a planet of radius $R$ and uniform mass density $\rho$. A particle is released into the tunnel. What is the angular frequency of oscillation of the particle ($\omega$) equal to? (Symbols carry their usual meaning)

   1. A.$\omega =\sqrt{\frac{4\pi G\rho }{3}}$
   2. B.$\omega =\sqrt{\frac{2\pi G\rho }{3}}$
   3. C.$\omega =\infty$
   4. D.$\omega =0$
   Show answer

   Answer: A

9. Q612026 · 13 Sept 2026

   On a rainy day, rain drops fall vertically with speed v. An observer is moving towards east with speed v, while another observer moves towards north with the same speed v. What is the angle between apparent rain directions observed by them?

   1. A.0°
   2. B.30°
   3. C.45°
   4. D.60°
   Show answer

   Answer: D

10. Q622026 · 13 Sept 2026

    What is the minimum horizontal speed given to the bob of a simple pendulum of length $50\mathrm{cm}$ so that it describes a complete circle? (Take $g=10m/{\mathrm{s}}^2$)

    1. A.$5m/s$
    2. B.$7.5m/s$
    3. C.$10m/s$
    4. D.$12.5m/s$
    Show answer

    Answer: A

11. Q632026 · 13 Sept 2026

    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

    Answer: C

12. Q642026 · 13 Sept 2026

    A biconvex lens is made of a material of refractive index 2 such that the ratio of the radii of curvature of its two faces is 1 : 2. A point source in air is placed on the principal axis of this lens at a distance u from the lens. Which one of the following is correct if the image is formed exactly at the same distance as that of the point source? (where R is the radius of curvature of the first face)

    1. A.u = R
    2. B.u = 2R
    3. C.2u = 3R
    4. D.3u = 4R
    Show answer

    Answer: D

13. Q652026 · 13 Sept 2026

    In a carrom game, a striker of mass 15 g hits a coin of mass 5 g head on and the coin moves with a speed of 0.36 m/s. If the time of contact between the striker and the coin is 3 milliseconds, then what is the average force applied by the striker on the coin?

    1. A.0.72 N
    2. B.0.60 N
    3. C.0.54 N
    4. D.0.30 N
    Show answer

    Answer: B

14. Q662026 · 13 Sept 2026

    A hollow prism is filled with water of refractive index 1.34 and white light is incident on the prism. The white light is assumed to have wavelengths ranging from 4020 Å to 6700 Å. What is the corresponding wavelength range in water?

    1. A.3000 Å to 5000 Å
    2. B.4020 Å to 6700 Å
    3. C.5000 Å to 7000 Å
    4. D.5386 Å to 8978 Å
    Show answer

    Answer: A

15. Q672026 · 13 Sept 2026

    A heating filament and an ideal resistor of fixed value are connected in series with a DC voltage source. After some time, the filament has reached its operating point so that the current in the circuit is steady. Which one of the following is correct?

    1. A.The steady current is larger than the initial value.
    2. B.The steady voltage across the ideal resistor decreases as compared to its initial value.
    3. C.Overall resistance of the circuit decreases.
    4. D.Power dissipation through the filament increases as compared to its initial value.
    Show answer

    Answer: B

16. Q682026 · 13 Sept 2026

    Two astronauts X and Y float in deep space far from external forces. Initially, they are at rest relative to one another. X throws a tool towards Y. Consider the two astronauts and the tool as one system. Which one of the following statements is correct?

    1. A.The centre of mass of the system moves towards Y.
    2. B.X moves and the centre of mass of the system follows him.
    3. C.The centre of mass follows the tool.
    4. D.The centre of mass remains fixed.
    Show answer

    Answer: D

17. Q692026 · 13 Sept 2026

    A uniform rope hangs symmetrically over a smooth pulley. One end of the rope is given a slight mass, making that side slightly heavier. Which one of the following is correct?

    1. A.As the rope starts moving, every point on the rope has the same acceleration.
    2. B.As the rope starts moving, every point on the rope has the same speed, but not the same acceleration.
    3. C.As the rope starts moving, the tension remains the same throughout the rope.
    4. D.As the rope starts moving, the centre of mass remains stationary.
    Show answer

    Answer: B

18. Q702026 · 13 Sept 2026

    An insulating container contains $250\mathrm{g}$ of water at $20^{\circ }\mathrm{C}$. Steam at $100^{\circ }\mathrm{C}$ is passed through it, heating it up to $25^{\circ }\mathrm{C}$. During this process, part of the steam also gets condensed, raising the mass of water to $252\mathrm{g}$. If the specific heat of water is $1\mathrm{Cal}{\mathrm{g}}^{-1}{}^{\circ }{\mathrm{C}}^{-1}$, then what is the value of the latent heat of steam?

    1. A.$530Cal/g$
    2. B.$540Cal/g$
    3. C.$550Cal/g$
    4. D.$560Cal/g$
    Show answer

    Answer: C

19. Q712026 · 13 Sept 2026

    Three parallel glass slabs of refractive indices $1.5$, $\sqrt{3}$ and $1.5$ respectively have widths $2\mathrm{mm}$, $1\mathrm{mm}$ and $4\mathrm{mm}$. The combination is in air. Light is incident at the first slab at an angle of incidence $\pi /3$. What is the angle with respect to the normal at which the light will emerge from the final surface?

    1. A.$\pi /6$
    2. B.$\pi /4$
    3. C.$\pi /3$
    4. D.$\pi /12$
    Show answer

    Answer: C

20. Q722026 · 13 Sept 2026

    Consider three wires X, Y and Z of the same length such that the ratio of their conductivities is 1 : 2 : 3. Further, the cross-sectional area of wire Z is twice that of Y and the resistance of X is equal to the resistance of Z. What is the ratio of the resistance of Y to that of X?

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

    Answer: B

21. Q732026 · 13 Sept 2026

    Two point charges of 4 C and 16 C are kept at a distance of 0.18 m. A third point charge of 1 C is kept between them such that the potential energy of the system is minimum. What is the magnitude of the electric field at the 1 C charge?

    1. A.0
    2. B.$\frac{1}{4\pi {\epsilon }_0}\left(\frac{1}{9}\right)\mathrm{N}{\mathrm{C}}^{-1}$
    3. C.$\frac{1}{4\pi {\epsilon }_0}\left(\frac{2}{9}\right)\mathrm{N}{\mathrm{C}}^{-1}$
    4. D.$\frac{1}{4\pi {\epsilon }_0}\left(\frac{1}{18}\right)\mathrm{N}{\mathrm{C}}^{-1}$
    Show answer

    Answer: A

22. Q742026 · 13 Sept 2026

    Consider the following statements in respect of sound waves: I. The speed of sound waves decreases with an increase in temperature if the atmospheric pressure remains the same. II. The speed of sound waves increases with increasing humidity if the atmospheric pressure remains the same. III. The speed of sound waves is not affected by a change in atmospheric pressure, provided the temperature is kept constant. Which of the statements given above are correct?

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

    Answer: B

23. Q852026 · 13 Sept 2026

    What are the approximate percentages by mass of nitrogen and hydrogen respectively in urea?

    1. A.43% and 5%
    2. B.47% and 5%
    3. C.43% and 7%
    4. D.47% and 7%
    Show answer

    Answer: D

24. Q892026 · 13 Sept 2026

    Which of the following statements is/are correct in respect of Portland cement? I. Adding more water (higher water-cement ratio) accelerates the initial setting time of cement. II. The addition of a small percentage of gypsum gives the desired retardation. III. Gypsum is added during manufacturing to accelerate the setting time of cement. Select the answer using the code given below:

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

    Answer: D

25. Q652026 · 12 Apr 2026

    Consider the following statements: I. Pine oil is used as antifoaming agent in the emulsion paints. II. Protective colloids are used in the emulsion paints to decrease their stability. III. Driers having oxidizable oils are added to the emulsion paints to accelerate drying process. Which of the statements given above is/are correct?

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

    Answer: D