6. Amount of water vapour (gaseous) in a given volume of air (Cubic Meter) is known as :

(A) Mixing Ratio
(B) Relative Humidity
(C) Absolute Humidity
(D) Specific Humidity

Ans. (C) Absolute Humidity - The amount of water vapor present in a unit volume of air, usually expressed in kilograms per cubic meter. Absolute humidity does not fluctuate with the temperature of the air.

Relative humidity, expressed as a percent, measures the current absolute humidity relative to the maximum.

Specific humidity is a ratio of the water vapor content of the mixture to the total air content on a mass basis.

Mixing ratio is defined as the abundance of one component of a mixture relative to that of all other components.


Source : The Free Dictionary by Farlex and Wikipedia.org