The humid volume may be increased by increasing the

ANS:C - both (a) and (b).

The humid volume may be increased by increasing the humidity at constant temperature and increasing the temperature at constant humidity. Humid volume refers to the volume occupied by a given mass of moist air. It depends on both the temperature and humidity of the air.

• Increasing the humidity at constant temperature: When humidity increases at a constant temperature, the amount of water vapor in the air increases, leading to an increase in the humid volume. This is because the additional water vapor molecules occupy space within the air without causing a significant change in air temperature.
• Increasing the temperature at constant humidity: When temperature increases at a constant humidity level, the air expands due to thermal expansion, causing an increase in the humid volume. This expansion occurs regardless of the amount of water vapor present in the air.