Question

Assertion: A desert cooler cools better on a hot dry day.
Reason: On a hot dry day, the temperature is high and humidity is low. The water takes heat from the hot desert cooler and evaporates. The evaporation of water cools the pad and the circulating water.

a.) Both assertion and reason are correct and reason is the correct explanation for the assertion.
b.) Both assertion and reason are correct and reason is not the correct explanation for the assertion.
c.) Assertion is correct but Reason is not correct.
d.) Both assertion and reason are incorrect.

Answer 1

Hint: Evaporative coolers: It is a device that cools air through the evaporation of water. These are usually 80% - 90% efficient. They are different from the air-conditioning systems.

Complete Solution :
The cooling in a desert room cooler is brought about by the evaporation of water. A desert cooler cools better on a hot and dry day in light of the fact that the higher temperature on a hot day increases the rate of evaporation of water, and the dryness of air (low humidity of the air) additionally expands the rate of evaporation of water. Furthermore, because of the expanded rate of evaporation of water, a desert room cooler cools better on a hot and dry day.
So, the correct answer is “Option A”.

Note: The possibility to make a mistake is that the evaporation is inversely proportional to humidity. It means, when the rate of evaporation increases, humidity decreases, and vice-versa.