Question

why during hot summer days the water usually kept in an earthern pot ?

Answer 1

During hot summer days the water usually kept in an earthen pot because the earthen pot made up of clay having fine pores in it. When we fill water in the pot, the water comes out through these fine pores and evaporates by taking the energy from the surroundings. To get back the energy, the surroundings absorb energy from the pot and make the water in the pot cold.