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Question:- Light travels at the fastest speed in A. glass B. water C. hydrogen D. vacuum
Answer:- Option D
Question:- Railway tracks are banked on curves A. necessary centrifugal force may be obtained from the horizontal component weight of the train B. to avoid frictional force between the tracks and wheels C. necessary centripetal force may be obtained from the horizontal component of the weight of the train D. the train may not fly off in the opposite direction
Answer:- Option C
Question:- 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 A. metals have higher thermal capacity than plastics B. plastics have a lower density than metals C. metals are good conductor of heat D. plastics have a higher thermal conductivity than metals
Answer:- Option C
Question:- 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? A. 1.8 km, 0.15 km B. 2.2 km, 0.20 km C. 2.8 km, 0.25 km D. 3.3 km, 0.30 km
Answer:- Option D
Question:- Intensity of sound at a point is ____ its distance from the source. A. directly proportional to B. inversely proportional to C. directly proportional to square of D. inversely proportional to square of
Answer:- Option D
Question:- Of the four locations mentioned below the highest inside temperature will be attained in the pressure cooker operated with the pressure valve open A. at sea level B. at the top of Mt. Everest C. at a place in a valley below sea level D. in an aeroplane flying at a height of 10,000 m with inside pressure maintained at the sea level
Answer:- Option C
Question:- Radio telescopes are better than optical telescopes because A. they can detect faint galaxies which no optical telescope can B. they can work even in cloudy conditions C. they can work during the day and night D. All of the above
Answer:- Option D
Question:- Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit A. X-rays B. ultraviolet light C. visible light D. radio waves
Answer:- Option C
Question:- Mercury is commonly used as a thermometric fluid rather than water because A. specific heat of mercury is less than water B. specific heat of mercury is more than water C. mercury has greater visibility than water D. density of mercury is more than the water
Answer:- Option C
Question:- Optical fibre works on the A. principle of refraction B. total internal reflection C. scattering D. interference
Answer:- Option B
Question:- 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
Answer:- Option C
Question:- Supersonic plane fly with the speed A. less than the speed of sound B. of sound C. greater than the speed of sound D. of light
Answer:- Option C
Question:- Mach number is used in connection with the speed of A. sound B. aircraft C. spacecraft D. ships
Answer:- Option B
Question:- On a stationary sail boat, air is blown from a fan attached to the boat. The boat A. moves in opposite direction in which the air is blown B. does not move C. moves in the same direction in which air blows D. spins around
Answer:- Option B