ANS:C - Wet bulb temperature

During an evaporative cooling process with recirculated water supply, the partial pressure of vapor remains constant. Here's why:

• In an evaporative cooling process, water is evaporated into the air, causing the air temperature to decrease due to the latent heat of vaporization being absorbed by the water molecules as they transition from liquid to vapor phase.
• As water evaporates into the air, the partial pressure of water vapor in the air increases.
• However, in a system with recirculated water supply, the same water is continuously recirculated, so the total amount of water available for evaporation remains constant.
• As a result, the partial pressure of water vapor in the air, which represents the amount of water vapor present in the air, remains constant during the evaporative cooling process with recirculated water supply.