GK-Physics Question and Answer
GK-Physics Question and Answer
41. oil raise up the wick in a lamp. The principle involves
- the diffusion of oil through the wick
- the liquid state of oil
- capillary action phenomenon
- volatility of oil
42. Superconductors are substances which
- conduct electricity at low temperature
- offer high resistance to the flow of current
- offer no resistance to the flow of electricity
- conduct electricity at high temperatures
44. Railway tracks are banked on curves
- necessary centrifugal force may be obtained from the horizontal component weight of the train
- to avoid frictional force between the tracks and wheels
- necessary centripetal force may be obtained from the horizontal component of the weight of the train
- the train may not fly off in the opposite direction
45. On a cold day when a room temperature is 15oC, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15oC, because
- metals have higher thermal capacity than plastics
- plastics have a lower density than metals
- metals are good conductor of heat
- plastics have a higher thermal conductivity than metals
46. Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?
- 1.8 km, 0.15 km
- 2.2 km, 0.20 km
- 2.8 km, 0.25 km
- 3.3 km, 0.30 km
47. Intensity of sound at a point is ____ its distance from the source.
- directly proportional to
- inversely proportional to
- directly proportional to square of
- inversely proportional to square of
48. Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open
- at sea level
- at the top of Mt. Everest
- at a place in a valley below sea level
- in an aeroplane flying at a height of 10,000 m with inside pressure maintained at the sea level
49. Radio telescopes are better than optical telescopes because
- they can detect faint galaxies which no optical telescope can
- they can work even in cloudy conditions
- they can work during the day and night
- All of the above
50. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
- X-rays
- ultraviolet light
- visible light
- radio waves