Question

Explain in brief the function of an electric fuse in a domestic circuit. An electric heater of current rating 3 kW; 220 V is to be operated in an electric circuit of rating 5 A. What is likely to happen when the heater is switched 'ON'? Justify your answer with necessary calculation.

Answer 1

Electric fuse is a safety component connected in series with an electric circuit which provides protection to electric devices and appliances from excess current.

Power consumption of electric heater is 3kW = 3000W

V = 220V

I = 5A

We know, P = VI

= 220 x 5

= 1100W

Thus, maximum power that can be drawn from the circuit is 1100W.

Thus, If the electric heater is connected to the circuit and switched "ON", the circuit will get overloaded and fuse will be blown out.