Solution:
The above statement is true.When a liquid evaporates, the energy loss is compensated by absorbing the energy from the liquid particles from the surroundings. As evaporation causes cooling, this also makes the surroundings cool. So, when the water is evaporated from a desert cooler, it absorbs energy from the surroundings and makes the surroundings cool. Evaporation depends on humidity, the amount of water vapour in the air. If the humidity is less, evaporation is more; if the humidity is more, evaporation is less. On a hot and dry day, the amount of water vapour in humidity air is less. So, the water inside the desert cooler evaporates faster, cooling the surrounding even more. That is why a desert cooler cools better on a hot day.
