Heating Effect of Electric Current

HEATING EFFECT OF ELECTRIC CURRENT

When electric current flows through a metallic conductor then heat is produced.

This is because when we convert electricity to other forms of energy, some energy is converted to useful work, but a certain amount is converted to heat energy. This is the heating effect of current. This is called Joule heating, ohmic heating, or resistive heating.

Electric Power

The rate of doing work or the rate of consumption of electrical energy is called Electric Power. If W is work done in time t, then 

P=W/t.

The work done in moving the charge Q through a potential difference V is VQ.

P = VQ/t = VI

This energy gets dissipated in the resistor as heat. Thus for a steady current I, the amount of heat H produced in time t is

H =VIt

This kind of heating does not depend on the direction of the current flow.

The amount of heat generated (H) is also given by the following relation.

H = I2Rt

where,

I is the electric current through the component

R is the resistance

t is the time span of heat generation

Uses of Heating Effect of Electric Current

The heating effect of current is applied in the working of electrical heating appliances such as electric kettles, electric iron, room heaters, water heaters (geysers), etc.