Question

The relative humidity h is a measure of air's capacity, at its existing temperature, to absorb further moisture, and is defined by the relation
1. \(\frac{e}{{{e_s}}} \times 100\)
2. \(\frac{{{e_s}}}{e} \times 100\)
3. \(\frac{{{2e_s}}}{e} \times 100\)
4. \(\frac{{{2e}}}{e_s} \times 100\)

Answer 1

Correct Answer - Option 1 : \(\frac{e}{{{e_s}}} \times 100\)

Concept:

Relative Humidity:

1. It is the amount of water vapour present in air expressed as percentage of the amount needed for saturation at the same temperature.

2. It is the ratio of partial pressure of water vapours to the saturation vapour pressure of water at given temperature.

\(Relative\;Humidity = \frac{e}{{{e_s}}} \times 100\)

Where: e = vapour pressure

es = saturation vapour pressure

3. It depends on temperature and the pressure of the system of interest.

4. Same amount of water vapour results in higher relative humidity in cool air than warm air.

5. Dew point is the temperature to which air must be cooled to become saturated with water vapour. When cooled further, the airborne water vapour will condense to form liquid water.

6. When the temperature below the freezing point of water, the dew point is called frost point.

7. Hygrometer is a device which is used for measuring the humidity of the air.