light, heat, thermodynamics, wave motion, sound, optics & oscillations - Category wise Question and Answer Practice Test with Solutions

Question : 26

The sound travels fastest in

a) liquids

b) solids

c) gases

d) none of these

Question : 27 [NDA]

In a sitar wire which one of the following types of vibration is produced?

a) Stationary longitudinal

b) Progressive longitudinal

c) Progressive transverse

d) Stationary transverse

Question : 28

Smoke emerging from a campfire at the bottom of a hill is being observed by a person at some distance, as shown in the figure. It is evening and the sun has just set behind the hill. Consider regions I and II of the smoke going up the sky

a) region I will be slightly brighter than the hill and region II will be slightly darker than the sky

b) region I will be slightly brighter than the hill and region II will be slightly brighter than the sky

c) region I will be slightly darker than the hill and region II will be slightly brighter than the sky

d) region I will be slightly darker than the hill and region II will be slightly darker than the sky

Question : 29 [RAS/RTS (Pre) 2007]

At what point the Fahrenheit temperature is double of Centigrade temperature?

a) – 12.3°C

b) 12.3°C

c) – 6.7°C

d) 160°C

Question : 30 [UPPCS (Pre) 2007]

Food gets cooked faster in a pressure cooker because

a) Water starts boiling at a higher temperature due to high pressure

b) Water boils only at 100ºC but the heat content is higher at high pressure

c) Water starts boiling at a lower temperature due to high pressure

d) Convection currents are set inside the cooker