Saturation Specific Humidity at Various Temperatures

Saturation specific humidity at various temperatures.Saturation specific humidity is the maximum possible water vapor in a mass of water vapor per unit mass of air (g/kg) .

If a kilogram of air at 20°C (68°F) has a specific humidity of 7.5 g/kg,the relative humidity is

A) 10%.
B) 25%.
C) 50%.
D) 75%.
E) 100%.