What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
The heat H produced by a resistor of resistance R due to current flowing through it for time t is H= I2Rt. It is also called ohmic heating and resistive heating.
In a conductor when voltage is applied across its ends, the free electrons available in it start drifting opposite to the direction of the positive terminal. These electrons collide with the positive ions (atoms which have lost the electrons). As a result of these collisions some energy of the electrons is transferred to the positive ions which
vibrate violently as they gain energy. Thus, heat is developed in the conductor.
Lesser the value of resistance higher the value of heat produced.
The four applications using heating effect of current are as follows
(i) Heating Rod
(ii) electric fuse
(iii) Electric iron
(iv) Incandescent Bulb