ANS:D - Relative saturation of unsaturated mixture of water vapor & air can not be increased by either reducing the mixture temperature or by increasing the total pressure.

The wrong statement is: For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same. Explanation:

• The wet bulb temperature and the adiabatic cooling lines are different on a psychrometric chart.
• The wet bulb temperature represents the lowest temperature that can be achieved by evaporating water into the air at constant pressure.
• The adiabatic cooling line represents the temperature decrease that occurs when air is cooled adiabatically (without heat exchange with the surroundings) by expanding or reducing pressure.
• These two lines are distinct and serve different purposes on a psychrometric chart.
• The wet bulb temperature is a measure of humidity and is influenced by the moisture content of the air, while the adiabatic cooling line represents changes in temperature due to pressure changes.
• Therefore, the wet bulb temperature and adiabatic cooling lines are not the same on a psychrometric chart.