Subtopic: Psychrometry – properties of air-water vapour mixture
Question Statement:
During an adiabatic sensible heating process of drying air in a steam coil heater, which psychrometric property remains strictly CONSTANT?
Options:
(A) Relative humidity
(B) Humidity ratio (specific humidity $W$)
(C) Dry bulb temperature
(D) Enthalpy
Answer Key:
B
Step-by-Step Solution & Explanation
Sensible heating merely adds sensible heat without adding or removing moisture. Hence, the humidity ratio (specific humidity $W$, $\text{kg/kg dry air}$) remains strictly constant along a horizontal line on the psychrometric chart.