41. Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
A. 4.2 seconds
B. 42 seconds
C. 4.2 years
D. 42 years
✅ The correct answer is option C.
Physics MCQs
42. An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at point B. The distance AB is
A. 1200 m
B. 0.33 km
C. 3.33 km
D. 33 km
✅ The correct answer is option C.
43. Sound of frequency below 20 Hz is called
A. audio sounds
B. infrasonic
C. ultrasonic
D. supersonics
✅ The correct answer is option B.
44. Of the following natural phenomena, tell which one known in Sanskrit as ‘deer’s thirst’?
A. Rainbow
B. Earthshine
C. Halo
D. Mirage
✅ The correct answer is option D.
45. Superconductors are substances which
A. conduct electricity at low temperature
B. offer high resistance to the flow of current
C. offer no resistance to the flow of electricity
D. conduct electricity at high temperatures
✅ The correct answer is option C.
46. Metals are good conductors of electricity because
A. they contain free electrons
B. the atoms are lightly packed
C. they have high melting point
D. All of the above
✅ The correct answer is option A.
47. Mirage is due to
A. unequal heating of different parts of the atmosphere
B. magnetic disturbances in the atmosphere
C. depletion of ozone layer in the atmosphere
D. equal heating of different parts of the atmosphere
✅ The correct answer is option A.
48. It takes much longer to cook food in the hills than in the plains, because
A. in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
B. due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil
C. in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere
D. in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking
✅ The correct answer is option A.
49. Optical fibre works on the
A. principle of refraction
B. total internal reflection
C. scattering
D. interference
✅ The correct answer is option B.
50. oil raise up the wick in a lamp. The principle involves
A. the diffusion of oil through the wick
B. the liquid state of oil
C. capillary action phenomenon
D. volatility of oil
✅ The correct answer is option C.