Principle of heat exchange:

Explanation

(i) When a hot and a cold object are kept in contact, then Heat lost by hot object in contact,then Heat lost by hot object = Heat gained by cold object. [In an isolated environmet ] .
(ii) When a hot object and cold object are placed in contact, then there is transfer of heat form hot object to cold object till the temperature of both become equal .
(iii) If there is not other loss or gain of heat energy form the surrouding , then principle of heat exchange is written as .
Heat lost by hot body = Heat gained by cold body.