Question

1) What is the function of earth wire in electrical instruments.2) Explain what is short circuiting in electric supply.3)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 ?All three questions together carry 3 marks .

Answer 1

1) The main function of the earth wire is to prevent live wire from overloading and absorbs the excess electrons & flows to beneath the ground . It is necessary to protect the appliances from any kind of damage.

2) When neutral and phase wire touch each other, the resistance becomes low and a heavy current flows through the circuit damaging the appliances connected to it.

3) (a) 5A
(b) 15A