Tuesday, 25 May 2021

UPSC CAPF (AC) exam 2016 - 2020: Physics MCQs

 

UPSC CAPF (AC) EXAM 2016 – 2020: Physics MCQs

 

1. Which of the following statements is/are correct?

 1. Gravitational waves were predicted by Albert Einstein in 1916 on the basis of his theory of General Relativity

 2. Gravitional waves do also exist in the Newtonian theory of Gravitation

  3. Gravitational waves are to be detected by very sensitive detectors known as interferometers

Select the correct answer using  the code given below:

(a) 1 only

(b) 1 and 3 only

(c) 2 and 3 only

(d) 1, 2 and 3

 

2. Let a resistor having 4 ohm resistance be connected across the terminals of a 12 volt battery. Then the charge in coulomb passing through the resistor per second is:

(a) 12

(b) 4

(c) 3

(d) 0.33

 

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

(a) The earth’s magnetic field is due to the motion of metals like Iron and nickel in the core of the earth

(b) The magnetic field lines of force are widely separated near the poles of a magnet but these lines come closer to one another at other places

(c) If the cross – sectional area of a magnetic field increases but the flux remains the same, the flux density decreases

(d) When the speed of a conductor moving through a magnetic field is increased the induced voltage increases

 

4. A Barometer kept in an elevator reads 760 mm when the elevator is at rest. When the elevator moves in the upward direction with increasing speed, the reading of the Barometer will be:

(a) 760 mm

(b) < 760 mm

(c) > 760 mm

(d) Zero

 

5. Which one of the following statements is correct?

(a) Acceleration due to gravity decreases with the increase of altitude

(b) Acceleration due to gravity increases with the increase of depth (assuming earth to be a sphere of uniform density)

(c) Acceleration due to gravity decreases with the increase of latitude

(d) Acceleration due to gravity is independent of the mass of the earth

 

6. Which one of the following statements is not true?

(a) The gravitational force of earth acting on a body of mass 1 kg is 9.8 newton

(b) The force acting on an object of mass 5kg moving with a uniform velocity of 10 m/s on a frictionless surface is Zero

(c) The SI unit of weight is kg

(d) The momentum of a man having mass

 

7. A piece of stone tied to a string is made to revolve in a circular orbit of radius r with other end of the string as the centre. If the string breaks the stone will

(a) move away from the centre

(b) move towards the centre

(c) move along a tangent

(d) Stop

 

8.  Consider the following physical quantities: Energy, power, pressure, impulse, temperature, gravitational potential

Which of the above is/ are the vector quantity/ quantities?

(a) Impulse only

(b) Impulse and pressure only

(c) Impulse, temperature and pressure

(d) Gravitational potential

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

(a) The rate of evaporation depends on temperature

(b) The rate of evaporation does not depend on surface area exposed to the atmosphere but on volume of the liquid

(c) The rate of evaporation depends on humidity of the surroundings

(d) The rate of evaporation depends on the wind speed

 

10. Water at 273 K is less effective in cooling than ice at the same temperature. It is because:

(a) water is difficult to handle

(b) Water at 273 K has less energy than ice at the same temperature

(c) Water at 273 K has more energy than ice at the same temperature

(d) Water is not a cooling agent

 

11. Presence of Ozone in the atmosphere is important because it absorbs

(a) Ultraviolet – A and Ultraviolet B radiations

(b) Ultraviolet – B radiations only

(c) infrared B radiations only

(d) outgoing ultraviolet B radiations and incoming ultraviolet A radiations

 

12. Statement I: Sound waves can travel through vacuum

      Statement II: Light is an electromagnetic wave and can travel through vacuum

(a) Both the statements are individually true and statement II is the correct explanation of statement I

(b) Both the statements are individually true but statement II is not the correct explanation of statement I

(c) Statement I is true but statement II is false

(d) Statement I is false but statement II is true

 

13. Statement I: A compass needle placed near a current – carrying wire will get deflected

      Statement II: A current carrying wire creates magnetic field around it

(a) Both the statements are individually true and statement II is the correct explanation of statement I

(b) Both the statements are individually true but statement II is not the correct explanation of statement I

(c) Statement I is true but statement II is false

(d) Statement I is false but statement II is true

 

14. Which one of the following processes is not a part of long wave radiation?

(a) Conduction

(b) Scattering

(c) Convection

(d) Radiation

 

15. The term LASER stands for

(a) Light Amplification by Stimulated Emission of Radiation

(b) Light Amplification by Spontaneous Emission of Radiation

(c) Light Amplification by Stimulated Emission of Rays

(d) Light Amplification by Stimulated Energy of Radiation

 

16. If the amplitude of Oscillation of a simple pendulum is very small, then its period of oscillation

 1. depends on the length of the pendulum, L

 2. depends on the acceleration due to gravity, g

 3. dpeneds upon the mass of the bob of the pendulum, m

 4. does not depend upon the amplitude of the pendulum, A

Select the correct answer using the code given below

(a) 1, 2 and 3

(b) 1, 2 and 4

(c) 2, 3 and 4

(d) 1 and 4 only

 

17. Lowering the atmospheric pressure on a liquid

(a) increases the boiling point of the liquid

(b) lowers the boiling point of the liquid

(c) does not affect the boiling point of the liquid

(d) increases the time required for it to boil

 

18. Which of the following statements about Optical microscope is/are correct?

 1. Both the eyepiece and objective of a microscope are convex lenses

 2. The magnification of a microscope increases with increase in focal length of the objective

 3. The magnification of a microscope depends upon the length of the microscope tube

 4. The eyepiece of a microscope is a concave lens

Select the correct answer using the code given below

(a) 1 and 3

(b) 3 only

(c) 3 and 4

(d) 1, 2 and 4

 

19. The optical phenomenon that is responsible for the propagation of light signal through an optical fibre is

(a) interference

(b) scattering

(c) total internal reflection

(d) refraction

 

20. Which one of the following phenomena cannot be exhibited by sound waves?

(a) Reflection

(b) Refraction

(c) Interference

(d) Polarisation

 

21. When a beam of white light is allowed to fall on a prism, the maximum deviation of the emerging light occurs for

(a) red light

(b) violet light

(c) Yellow light

(d) blue light

 

22. Which one of the following is not a luminous object?

(a) Sun

(b) Electric lamp

(c) Candle

(d) Moon

 

23. Brilliance of diamond is due to

(a) interference of light

(b) diffraction of light

(c) polarization of light

(d) total internal reflection of light

 

24. Which one of the following is NOT an electromagnetic wave?

(a) Light wave

(b) Radio Wave

(c) Sound wave

(d) Micro wave

 

25. Which one of the following is NOT true for an electromagnetic wave?

(a) Electromagnetic wave transports energy and momentum

(b) Electromagnetic wave can be polarized and reflected

(c) Electromagnetic wave is longitudinal

(d) Electromagnetic wave propagation is described by the varying electric and magnetic fields

 

26. A snowboard pulled up by a tow rope travels at the rate of 5m/s up a mountain. If 3000 watt of power is used, what force was applied to it?

(a) 50 N

(b) 100 N

(c) 600 N

(d) 15000 N

 

27. When a longitudinal wave moves through a certain medium, the quantity which is transmitted through the medium is

(a) material of the medium only

(b) energy only

(c) both material of the medium and energy

(d) none of the above

 

28. Which one of the following statements on photoelectric effect is NOT correct?

(a) Albert Einstein received the nobel prize for explaining photoelectric effect

(b) For each metal, there is a threshold frequency V0 below which this effect is not observed

(c) At a frequency v > v0, the kinetic energy of ejected electrons does not change on increasing the frequency of incident light

(d) The number of electrons ejected is proportional to the intensity of incident light

 

29. Latent heat corresponds to the change in heat at constant

(a) temperature only

(b) volume only

(c) Pressure only

(d) temperature, volume and pressure

 

30. Which one of the following statements with regard to Newton’s third law of motion is NOT correct?

(a) Force never occurs singly in nature

(b) When the earth pulls a stone downwards due to gravity, the stone exerts a force on the earth

(c) There is a cause – effect relation implied in the third law

(d) There is no cause – effect relation implied in the third law

 

31. The radar used by police to check over speeding vehiles works on the principle of

(a) Raman effects

(b) Induction effect

(c) Doppler effect

(d) Coulomb effect

 

32. Which one of the following statements regarding motion is correct?

(a) All the periodic motions are necessarily simple harmonic

(b) All the simple harmonic motions are necessarily periodic motions

(c) There is no co –relation between the simple harmonic motions and the periodicity of motion

(d) The relation between the simple harmonic motion and periodic motion depends upon the mass of object undergoing the motion

 

33. Which one of the following statements regarding Fleming’s Rule is correct?

(a) Fleming’s left hand rule gives direction of force on a current carrying conductor in a magnetic field

(b) Fleming’s right hand rule gives direction of force on a current carrying conductor in a magnetic field

(c) Both the left hand and right hand rule can be used  for finding direction of force on a current carrying conductor in a magnetic field

(d) Fleming’s rules has nothing to do with magnetic field

 

34. Two magnetic field lines produced by the same source

(a) never intersect

(b) can originate from same point

(c) can terminate at same point

(d) can intersect depending on situation

 

35. Which one of the following statements for an object falling freely under the influence of gravity is correct?

(a) Zero acceleration always implies  zero velocity

(b) Zero acceleration has no relation with the velocity of the object

(c) Zero velocity at any instant necessarily means Zero acceleration at that instant

(d) Acceleration is constant all throughout the free fall