COOLING EFFECTS OF EVAPORATION

 How does water kept in an earthen pot become cool during summer?

Earthen pot which is made up of clay has lot of very very small pores on it. A little amount of water comes out through that pores get evaporated quickly. Evaporation take place by absorbing heat energy from the surroundings. As a result of evaporation, pot cools down and water inside that also get cooled.