Physics - Study Mode

[#1066] Wollen clothes keep the body warm because
Correct Answer

(B) Wool is a bad conductor

Explanation

Solution: Wool does not allow heat to pass on from body to surrounding because it is a bad conductor of heat. So, the body is kept warm.

[#1067] Plants are dried up in winter due to frost because
Correct Answer

(D) There is mechanical loss of tissues and drought condition prevails

Explanation

Solution: The rate of respiration is dependent on temperature: The warmer it is, the more a plant will respire. Extreme winter cold and frost are similar to summer drought in that frozen water is unavailable to the plant. The air is very dry as well.

[#1068] A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?
Correct Answer

(D) Conduction, convection and radiation

Explanation

Solution: A cup of hot coffee is placed on a metal table in a room can lose heat via conduction, convection and radiation.

[#1069] In general, which is the cause of a land breeze?
Correct Answer

(C) Temperature

Explanation

Solution: Temperature is the cause of land breeze in general.

[#1070] A person does some work of 1,000 J in 2 s. His power will be ________
Correct Answer

(C) 500W

Explanation

Solution: Power = work / time = 1000 / 2 = 500 W