Question

A wet cloth is wrapped around a water storage containers in summer

Answer 1

so that the container and it's contents remain cool and be unaffected by the outside temperature. The water in the cloth plays a role here.

Answer 2

The following are the reasons why a wet cloth is wrapped around water storage containers:

1. In summers the temperature is usually very high and water evaporates from the moist material and makes it drained. The earthen pots are permeable, taking the external heat and make the stuff wet. This method of moistening and dehydrating repeats and make the water in the container remains chilly.

2. An earthen pot has tiny pores in its surfaces. When water is poured into it, some of it leaks through these orifices onto its external surface. On leading there, it evaporates. The energy needed for evaporation is taken from the clay pot and from the liquid in it. As a result, the water in a clay pot becomes cooled.