Q. – Water in an earthen pot remains cold even in summer. Why?

Ans – As we know that earthen pot is porous. Water kept in earthen pot comes on outer surface of the pot because of its tiny pores. 

Water on surface gets evaporated. For evaporation it needs heat. It absorbs partially heat from atmosphere and partially from water in pot and get evaporated. Continous absorption of heat from water in pot makse it cool.