Question:-
Consider the following statements:
1. The specific humidity is the ratio of the mass of water vapour to the mass of dry air in a given volume of the mixture
2. The relative humidity of the atmospheric air is the ratio of the actual mass of the water vapour in a given volume to that which it would have if it were saturated at the same temperature
3. The degree of saturation is defined as the ratio of the specific humidity of a mixture to the specific humidity of the mixture when saturated at the same temperature
Which of the statements given above are correct?
Option (A)
1 and 2
Option (B)
2 and 3
Option(C)
1 and 3
Option(D)
1, 2 and 3
Correct Option:
(D)
Question Solution:
Specific humidity, humidity ratio, or moisture content: It is the mass of water vapour present in 1 kg of dry air (in the air-vapour mixture). It may also be defined as the ratio of mass of water vapour to the mass of dry air in a given volume of the air-vapour mixture.
w = (0.622Pv/(P-PV))
Relative humidity: Relative humidity is the ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure.
i.e. Æ = (mv/ms) = (Pv/Ps)
Degree of saturation or percentage humidity: It is the ratio of actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at same temperature. In other words, it may be defined as the ratio of actual specific humidity to the specific humidity of saturated air at the same dry bulb temperature.
i.e. m = (w/ws)