Question

The units of Relative Humidity are
(A) $kg - {m^3}$
(B) $kg$
(C) $kg - {m^2}$
(D) none of these

Answer 1

Hint:The relative humidity is given by the ratio of the actual humidity and the absolute humidity. So since the terms on both the numerator and the denominator of the fraction will have similar units. So the term will have no unit.

Formula Used: In this solution we will be using the following solution,
$RH = \dfrac{{{\text{Actual humidity}}}}{{{\text{absolute humidity}}}}$
where $RH$ is the relative humidity.

Complete Step by Step Solution: The term humidity means the concentration of the water vapour that is present in the air. The relative humidity is always expressed as a percentage. It is the present state of the absolute humidity as compared to the maximum humidity at that given temperature.
Therefore we can write the formula for the relative humidity as,
$RH = \dfrac{{{\text{Actual humidity}}}}{{{\text{absolute humidity}}}}$
Now, since in the formula for the relative humidity both the terms are that of humidity. So the units of both the terms are the same in the fraction.
Therefore, the units in the numerator and the denominator cancel out and we don’t get any unit for the relative humidity.
Hence, the relative humidity has no units, and so the answer will be none of these.

So the correct answer will be option D. none of these.

Note: The humidity plays a very important role in life on earth. It helps to regulate the internal body temperature for the animals that sweat. In case of high humidity, the rate of evaporation of sweat from the skin surface decreases, which impairs heat exchange. There are mainly three types of humidity: the absolute humidity, relative humidity and the specific humidity.