Question

formation of clouds is a physical change explain

Answer 1

Physical changes include changes that do not result in the chemical alteration of the substance(s) in question. In this case, water that has evaporated just condenses to form clouds. This is simply a change of state from liquid (vapor) to solid. 

Answer 2

Clouds are formed by the condensation of of water vapours present in the atmosphere. When when rain water goes back on the earth, no new product is formed. Therefore, it is a physical change.