Earthing and Fuses Prevent Fires and Shocks

Question 1

If a fault develops in which the live somehow touches the metal case, what happens? (When case is earthed)

Answer 1

A big current flows through the live wire, the case and the earth wire

Question 2

What does this surge in current do?

Answer 2

‘Blows’ (melts) the fuse (or trips the circuit breaker) which cuts off the live supply

Question 3

What does the cutting off of the live supply do to the whole appliance?

Answer 3

Isolates it, making it impossible to get an electric shock from the case

Question 4

What does it also prevent the risk of?

Answer 4

Fire caused by the heating effect of a large current