45 Important Physics Questions for NDA Exam (based on Previous Papers)

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• Jun 14, 2018 - 11:0

Physics is a very important sub-section of the General Ability test of NDA & NA exam. Almost 23-25 questions are asked from the different topics of Physics in the NDA exam. So, for all the aspirants preparing for the exam, here are 45 important Physics questions for the NDA and NA exam based on previous year papers. The NDA physics questions shared below will help you understand the type of questions which are commonly asked in this sub-section.
So, without any delay, go through these physics questions for the NDA exam now, understand the concepts which are used in them and practice them properly for an effective preparation of National Defence Academy (NDA) and Naval Academy (NA) exam!

Note: We will add more important Physics questions asked in the previous years of NDA exam shortly in this post and will also share a PDF for the same for better preparation!

Physics Questions asked in NDA & NA Exam 2018

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

(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).
(b) The centripetal acceleration is greater for a gentle curve than that for a sharp curve.
(c) The centripetal acceleration is the same for both, the gentle and sharp curves.
(d) The centripetal acceleration causes the object to slow down

2. The force acting on a particle of mass m moving along the x-axis is given by F(x) = Ax² - Bx. Which one of the following is the potential energy of the particle?

(a) 2Ax - B
(b) - x²/6 (2Ax-3B)
(c) Ax³ -Bx²
(d) Zero

3. The symbol of SI unit of inductance is H. It stands for

(a) Holm
(b) Halogen
(c) Henry
(d) Hertz

4. In a vacuum, a five-rupee coin, a feather of a sparrow bird and a mango are dropped simultaneously from the same height. The time taken by them to reach the bottom is t 1, t2 and t3 respectively. In this situation, we will observe that

(a) t₁ > t₂ > t₃
(b) t₁ > t₃ > t₂
(c) t₃ > t₁ > t₂
(d) t₁ = t₂ = t₃

5. Electron emission from a metallic surface by application of light is known as

(a) Thermionic emission
(b) Photoelectric emission
(c) High field emission
(d) Auto-electronic emission

6. How long does light take to reach the Earth from the Sun?

(a) About 4 minutes
(b) About 8 minutes
(c) About 24 minutes
(d) About 24 hours

7. Radioactivity is measured by

(a) GM Counter
(b) Polarimeter
(c) Calorimeter
(d) Colorimeter

8. The mirrors used as rear-view mirrors in vehicles are

(a) concave
(b) convex
(c) cylindrical
(d) plane

9. Which one of the following waves is used for detecting forgery in currency notes?

(a) Ultraviolet waves
(b) Infrared waves
(c) Radio waves
(d) Microwaves

10. Water boils at a lower temperature at high altitudes because

(a) the air pressure is less
(b) outside temperature is less
(c) latent heat is less
(d) None of the above

11. Concave mirror is used in headlights of vehicles, because it

(a) focuses light from the bulb onto nearby vehicles
(b) sends parallel rays
(c) fits well into the shape of the headlight
(d) is cheaper than other mirrors

12. If some object is weighed when submerged in water, what will happen to its weight compared to its weight in air?

(a) Increase
(b) Decrease
(c) Remain exactly the same
(d) Increase or decrease cannot be predicted

13. Light year is a measure of

(a) time
(b) distance
(c) total amount of light falling on the Earth in a year
(d) average intensity of light falling on the Earth in a year

14. Which one of the following statements about energy is correct?

(a) Energy can be created as well as destroyed.
(b) Energy can be created but not destroyed.
(c) Energy can neither be created nor destroyed.
(d) Energy cannot be created but can be destroyed.

15. Which one among the following waves carries the maximum energy per photon?

(a) X-rays
(b) Radio waves
(c) Light waves
(d) Microwaves

16. A rainbow is produced due to which one of the following phenomena?

(a) Dispersion of light
(b) Interference of light
(c) Diffraction of light
(d) Scattering of light by atmospheric dust

17. Bats detect obstacles m their path by receiving the reflected

(a) Infrasonic waves
(b) Ultrasonic waves
(c) Radio waves
(d) Microwaves

18. The statement that 'heat cannot flow by itself from a body at a lower temperature to a body at a higher temperature', is known as

(a) Zeroth law of thermodynamics
(b) First law of thermodynamics
(c) Second law of thermodynamics
(d) Third law of thermodynamics

19. Which one of the following waves does not belong to the category of the other three?

(a) X-rays
(b) Microwaves
(c) Radio waves
(d) Sound waves

20. Which one of the following statements is not correct?

(a) Human eye is a refracting system containing a diverging lens
(b) The retina of the human eye contains millions of light sensitive cells, called rods and cones, which convert the light into electrical messages
(c) Every image that is focused on the retina is upside down
(d) We need both eyes to judge the relative positions of objects accurately

21. Which one of the following statements is not correct?

(a) Ultrasonic waves cannot get reflected, refracted or absorbed
(b) Ultrasonic waves are used to detect the presence of defects like cracks, porosity, etc. in the internal structure of common structure materials.
(c) Ultrasonic waves can be used for making holes in very hard materials like diamond.
(d) Ultrasonic waves cannot travel through vacuum.

22. Which one of the following statements is correct?

(a) Any energy transfer that does not involve temperature difference in some way is not heat.
(b) Any energy transfer always requires a temperature difference.
(c) On heating, the length and volume of the object remain exactly the same.
(d) Whenever there is a temperature difference, heat is the only way of energy transfer.

23. If ‘T’ is the time period of an oscillating pendulum, which one of the following statements is NOT correct?

(a) The motion repeats after time T only once
(b) T is the least time after which motion repeats itself.
(c) The motion repeats itself after nT, where n is a positive integer
(d) T remains the same only for small angular displacements

24. If an object moves with constant velocity, then which one of the following statements is NOT correct?

(a) Its motion is along a straight line
(b) Its speed changes with time
(c) Its acceleration is zero
(d) Its displacement increases linearly with time

25. An object is moving with uniform acceleration a. Its initial velocity is u and after time t its velocity becomes v. The equation of its motion is v = u + at. The velocity (along y-axis) time (long x-axis) graph shall be a straight line

(a) passing through origin
(b) with x-intercept u
(c) with y-intercept u(d) with slope u

27. What is the net force experienced by a bar magnet placed in a uniform magnetic field?

(a) Zero
(b) Depends upon the length of the magnet
(c) Never zero
(d) Depends upon temperature

28. Which one of the following has maximum inertia?

(a) An atom
(b) A molecule
(c) A one-rupee coin
(d) A cricket ball

29. Which one of the following is the value of 1 kWh of energy converted into joules?

(a) 1.8 x 10⁶ J
(b) 3.6 x 10⁶ J
(c) 6.0 x 10⁶ J
(d) 7.2 x 10⁶ J

29. Which one of the following statements about gravitational force is NOT correct?

(a) It is experienced by all the bodies in the universe
(b) It is a dominant force between celestial bodies
(c) It is a negligible force of atoms
(d) It is same for all pairs of bodies in our universe

30. Whether an object will float or sink in a liquid, depends on

(a) mass of the object
(b) mass of the object and density of liquid only
(c) difference in the densities of the object and liquid
(d) mass and shape of the object only

31. Which one of the following devices is non-ohmic?

(a) Conducting copper coil
(b) Electric heating coil
(c) Semi-conductor diode
(d) Rheostat

32. Which one of the following is the natural phenomenon based on which a simple periscope works?

(a) Reflection of light
(b) Refraction of light
(c) Dispersion of light
(d) Total internal reflection of light

33. Which one of the following frequency ranges is sensitive to human ears?

(a) 0 - 200 Hz
(b) 20 – 20,000 Hz
(c) 200 – 20,000 Hz only
(d) 2,000 – 20,000 Hz only

34. A ball balanced on a vertical rod is an example of

(a) stable equilibrium
(b) unstable equilibrium
(c) neutral equilibrium
(d) perfect equilibrium

35. Which of the following statements about a fluid at rest in a cup is/are correct?
1. Pressure is same at all the points in a fluid
2. Pressure is exerted on the walls
3. Pressure exists everywhere in the fluid
Select the correct answer using the code given below:

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 only
(d) 1, 2 and 3

36. Which one of the following devices is used to measure atmospheric pressure?

(a) Ammeter
(b) Barometer
(c) Potentiometer
(d) Lactometer

37. Which one of the following is an example of the force of gravity of the earth acting on a vibrating pendulum bob?

(a) Applied force
(b) Frictional force
(c) Restoring force
(d) Virtual force

38. Which one of the following statements about the refractive index of a material medium with respect to air is correct?

(a) It can be either positive or negative
(b) It can have zero value
(c) It is unity for all materials
(d) It is always greater than one

39. Which one of the following statements about magnetic field lines is NOT correct?

(a) They can emanate from a point
(b) They do not cross each other
(c) Field lines between two poles cannot be precisely straight lines at the ends
(d) There are no field lines within a bar magnet

40. Two convex lenses with power 2 dioptre are kept in contact with each other. The focal length of the combined lens system is

(a) 0.10 m
(b) 2 m
(c) 4 m
(d) 0.25 m

41. A body has a free fall from a height of 20 m. After falling through a distance of 5 m, the body would

(a) lose one-fourth of its total energy
(b) lose one-fourth of its potential energy
(c) gain one-fourth of its potential energy
(d) gain three-fourth of its total energy

42. Which of the following statements about electromagnetic waves, sound waves and water waves is/are correct?
1. They exhibit reflection
2. They carry energy
3. They exert pressure
4. They can travel in vacuum
Select the correct answer using the code given below:

(a) 1, 2 and 3
(b) 2 and 4
(c) 1 and 3 only
(d) 1 only

43. Thermal capacity of a body depends on the

(a) mass of the body only
(b) mass and shape of the body only
(c) density of the body
(d) mass, shape and temperature of the body

44. A container is first filled with water and then the entire water is replaced by mercury. Mercury has a density of 13.6 x 10³ kg/m³. If X is the weight of the water and Y is the weight of the mercury, then

(a) X = Y
(b) X = 13.6 Y
(c) Y = 13.6 X
(d) None of the above

45. Density of water is

(a) maximum at 0^oC
(b) minimum at 0^oC
(c) maximum at 4^oC
(d) minimum at -4^oC

All the best for your exams,

The squadrons of NDA!