Q. Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).
Assertion (A): Relative humidity decreases with increasing air temperature.
Reason (R): Absolute humidity increases with increasing evaporation.
Select the correct answer from the codes given below.
a) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
b) (A) is false, but (R) is true.
c) Both (A) and (R) are true and (R) is the correct explanation of (A).
d) (A) is true, but (R) is false.
Question from UPPSC Prelims 2024
Correct Answer: a) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
Explanation:
– Assertion (A): Relative humidity decreases with increasing air temperature.
This statement is true. Relative humidity is the ratio of the actual amount of water vapor in the air to the maximum amount of water vapor the air can hold at a given temperature, expressed as a percentage. As air temperature increases, the air’s capacity to hold water vapor increases, but if the actual amount of water vapor remains constant, the relative humidity decreases.
– Reason (R): Absolute humidity increases with increasing evaporation.
This statement is also true. Absolute humidity refers to the total amount of water vapor present in a given volume of air. When evaporation increases, more water vapor enters the air, leading to an increase in absolute humidity.
– However, (R) is not the correct explanation of (A). The decrease in relative humidity with increasing air temperature is due to the air’s increased capacity to hold water vapor, not directly because of evaporation or changes in absolute humidity.
