Which best describes how air moves during convection?
A. Cool air falls down
B. Warm air falls down
C. Cool air is replaced by warm air
D. Air always falls down
Answer: Option A
Solution(By Examveda Team)
In convection, hot air rises from the Earth's surface and becomes cold at higher altitude because of lower temperature there. As it cools, it sinks down to the surface of the Earth. On reaching Earth, it warms again and rises up again. The main reason for this phenomenon is - sinking cold air pushes the warm air up.This Question Belongs to General Knowledge >> Physics
Which of the following terms is not used in the field of physics?
A. Latent heat
B. Nuclear fusion
C. Refractive index
D. Stock value
Radiocarbon is produced in the atmosphere as a result of
A. Collision between fast neutrons and nitrogen nuclei present in the atmosphere.
B. Action of ultraviolet light from the sun on atmospheric oxygen.
C. Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere.
D. Lightning discharge in atmosphere.
It is easier to roll a stone up a sloping road than to lift it vertical upwards because
A. Work done in rolling is more than in lifting.
B. Work done in lifting the stone is equal to rolling it.
C. Work done in both is same but the rate of doing work is less in rolling.
D. Work done in rolling a stone is less than in lifting it.
The absorption of ink by blotting paper involves:
A. Viscosity of ink
B. Capillary action phenomenon
C. Diffusion of ink through the blotting
D. Siphon action
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