Unsaturated air (with dry and wet bulb temperatures being 35 and 25°C respectively) is passed through water spray chamber maintained at 35°C. The air will be

ANS:B - humidified

When unsaturated air is passed through a water spray chamber maintained at a temperature equal to the dry bulb temperature of the incoming air (35°C in this case), the air will be humidified. Here's why:

1. The dry bulb temperature of the air remains the same before and after passing through the water spray chamber because the temperature of the chamber is equal to the dry bulb temperature of the incoming air.
2. However, the air is unsaturated (i.e., its relative humidity is less than 100%), and as it passes through the water spray chamber, water droplets in the chamber evaporate into the air. This process adds moisture to the air without changing its temperature, increasing its humidity level. Therefore, the air is humidified.