Q6 of 33 Page 1

(i) What is the function of earth wire in electrical instruments?

(ii) Explain what is short-circuiting an electric supply.


(iii) What is the usual current rating of the fuse wire in the line to feed (a) Lights and fans? (b) Appliances of 2kW or more power?

(i) Earth wire protects the electrical appliances from getting damaged due to electrical shocks.


(ii) When live wire touches the neutral wires circuit offers very low resistance to the flow of current so a heavy current flows through the circuit hence electric short circuit occurs.
A short circuit is a direct connection between two points in a circuit that should not be connected, such as the two terminals of a power supply.


(iii) The usual current rating of the fuse wire in the line to feed (a) Lights and fans: 5 A


(b) Appliances of 2kW or more power: 15 A


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