Question

(a) What is meant by short-circuiting in electric supply?
(b) What is the function of earth wire in electrical instruments?
(c) What is the usual current rating of the fuse wire in the power supply line which runs
​(i) lights and fans, and (ii) appliances of 2 kW power?

Answer 1

(a) When the live wire comes in contact with the neutral wire, the electric supply is said to be short-circuited. Due to short-circuiting in electric supply, a high amount of current flows in the circuit, which may damage various electric appliances or even start a fire.

(b) The function of the earth wire in the electrical instruments is to provide an immediate path to excess or unnecessary current in the circuit into the ground. It reduces the chances of getting a shock.

(c) (i) The usual current rating of the fuse wire in the line which runs lights and fans is 5 A.
(ii)The usual current rating of the fuse wire in the line which runs appliances of 2kW or more power is 15 A.