Give a brief idea about principle explained in the following figure.

Explanation

1.The adjoining figure indicates principle of heat exchange.
2.If heat is exchanged between a hot and coId object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing due to loss of energy.
3. The change in temperature continues till the
temperatures of both the objects attain the same value.
4. In this process, the cold object gains heat energy and the hot object loses heat
energy.
5.If the system of both the objects is isolated from the environment by keeping it inside a heat resistant box, then no energy can flow from inside the box or come into the box.
6. In this situation, we get the following principle as
Heat energy lost by the hot object= Heat energy gained by the cold object.
This is called as 'Principle of heat exchange'.