Give reason for the following:

A hot air balloon rises up in the sky. 

Give reason for the following:

The water pipe in a solar water heater is bent into the shape as given in the picture.

A utensil, which is made of thick copper base, is placed on the gas burner to heat up water in it.

a) Describe briefly how heat is transferred:

i) From gas burner to water.

A utensil, which is made of thick copper base, is placed on the gas burner to heat up water in it.

a) Describe briefly how heat is transferred:

ii) Spread through water in the utensil.