Question

Why skin feels dry in an air-conditioned room?

• A. Because the rate of evaporation decreases with lower humidity.
• B. Because the rate of evaporation increases with lower humidity.
• C. Because the rate of evaporation remains same with lower humidity.
• D. Because the rate of evaporation increases with higher humidity.

Answer 1

The correct option is B Because the rate of evaporation increases with lower humidity.

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

When the humidity is lower, the air's capacity to absorb vapour is greater. The adhesive force of attraction between liquid molecules increases and more molecules escape into the atmosphere. Hence evaporation is greater in dry air.