Q1: The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C.

ANS:B - > 25

To determine the wet bulb temperature after heating the mixture to 45°C at constant pressure, we need to understand the relationship between wet bulb temperature and dry bulb temperature. The wet bulb temperature represents the lowest temperature that can be achieved by evaporating water into the air at constant pressure. It depends on both the dry bulb temperature (the actual temperature of the mixture) and the humidity of the air. Given that the dry bulb temperature (actual temperature) is 45°C after heating, and the wet bulb temperature before heating is 25°C, we know that the wet bulb temperature cannot exceed the dry bulb temperature. Therefore, the wet bulb temperature after heating the mixture to 45°C will be greater than 25°C. We can't determine the exact value without information about the humidity of the air, but it will definitely be higher than 25°C.