question_answer 30)

  During summer, water kept in an earthen pot becomes cool because of the phenomenon of (a) diffusion                       (b) transpiration               (c) osmosis                        (d) evaporation

Answer:

  (d) During summer, water kept in an earthen pot becomes cool because of the phenomenon of evaporation. Earthen pot 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. This water evaporates continuously and take the latent heat required for vaporization from the remaining water. In this way, the remaining water loses heat and gets cooled.