Question

how does the water kept in an earthen pot Matka become cool during summer

Answer 1

water in pot comes out of it through small pores and absorbes heat from water and surrounding to get evaporate. the heat absorbed from water leads to temperature of water due to decrease in its international energy and so water becomes cool.

hope this helped!

Answer 2

earthen pot has tiny pores present in it.during hot days water evaporates from these pores by gaining energy from its surroundings in form of vapour
as it used the energy to convert into vapor this cools the earthen pot.