During summer, water kept in an earthen pot becomes cool because of the phenomenon of
diffusion
transpiration
osmosis
evaporation

Correct Answer: (d) evaporation

Explanation: During summer, water kept in an earthen pot becomes cool because of the phenomenon of evaporation. The earthen pot (pitcher) has a large number of tiny pores in its walls and some of the water molecules continuously keep seeping through these pores to outside the pot.