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

Answer:

When the current in the circuit abruptly increases then short circuiting occurs

It prevents the user from severe shock

In lights and bulbs is 5A and in appliance of 2kw power is 15A

Answer 2

Explanation:

(a) When the neutral wire and the live wire meet each other, it creates a resistance that becomes zero. With this, the current’s Ohm’s law becomes infinite. When too many home appliances are connected in a single socket, a large amount of current is withdrawn. So, when wire insulation is damaged, short circuit happens.

(b) The important function of earth wire is the absorption of excess current that passes via the appliances protecting us from shocks.  

(c) Fuse wire is used in appliances for safety purposes. It helps to protect from short-circuiting, overloading and high voltage. It’s capacity in lights and fans is 5A; In 2kW appliances, its capacity is 15A.