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GCSE Standard Questions: Electricity in the Home

Q11. A washing machine is connected to the mains electricity supply using a cable and three-pin plug.

(a) Here is a three-pin plug.

(i) Name the material used for the outer casing of the plug - giving the reason why that material is used.

[1 mark]

(ii) Name the material used for the pins of the plug - giving the reason why that material is used.

[1 mark]

 

(b) The three-pin plug contains a fuse.

The fuse is connected to one of the wires inside the cable.

(i) Which one of the wires inside the cable is the fuse connected to?

[1 mark]

(ii) The fuse is a thin wire inside a closed glass tube. The wire acts as a resistor. What effect does a current through a wire have on the wire?

[1 mark]

(iii) The power of the washing machine varies between 0.7 kW and 2 kW depending on which part of the wash cycle is operating.

Calculate the maximum current drawn from the mains electricity supply by the washing machine. The mains electricity supply is at a potential difference of 230 V.

[4 marks]

(c) The diagram below shows how the mains electricity cable is connected to the washing machine. The earth wire is connected to the metal case of the washing machine.

If a fault makes the metal case live, the earth wire and fuse inside the plug prevent the mains cable from overheating and causing a fire. Explain how.

[3 marks]

(d) New research has shown that many people underestimate the hazards of using mains electricity. It is important that people do understand the hazards of using mains electricity. Suggest why.

[1 mark]

(Total 11 marks)