An electric hairdryer and an electric heater are linked to the mains supply, as illustrated in Fig. 7.1. The cable from the heater to the mains supply contains a live wire, a neutral wire and an earth wire.
(a)[1]
State the purpose of the neutral wire.
(b)[2]
The live wire in the electric heater touches the outer metal case. Explain how the earth wire and the fuse together keep the user safe from electric shock.
(c)[1]
The hairdryer has no earth wire. Explain why this hairdryer can still be used safely.
(d)[1]
In some modern homes, circuit breakers are fitted in place of fuses. Suggest one advantage of using a circuit breaker instead of a fuse.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Acts as return path to close the circuit” …