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Pearson Edexcel International GCSE (9–1) · PHYSICS · Section

ELECTRICAL POWER

16 practice questions

Start practising (16 questions)

Practice questions

11–16 of 16

  1. Question 11

    3 marks · Normal

    Look at these two electrical appliances:

    ApplianceWire materialWire resistance
    ToasterNichrome (metal alloy)High
    Mains cable in wallCopperLow
    (a)

    Explain why the heating element in a toaster uses a wire with high resistance, but the wires in a mains cable use low resistance copper.

    [3 marks]
    Answer and see the solution →

  2. Question 12

    1 mark · Normal

    Which of the following best describes the unit watt (W)?

    1. A.The energy transferred per coulomb of charge.
    2. B.The charge that passes a point every second.
    3. C.The energy transferred per second.
    4. D.The resistance to current flow in a circuit.
    Answer and see the solution →

  3. Question 13

    3 marks · Normal

    A mains-powered oven uses a heating element with a high resistance. The oven has a power rating of 2000 W and is switched on for 15 minutes.

    (a)

    State why the heating element must have a high resistance.

    [1 mark]
    (b)

    Calculate the total energy transferred to the oven in this time.

    [2 marks]
    Answer and see the solution →

  4. Question 14

    3 marks · Normal

    A student connects a thin filament lamp and a mains kettle in parallel to a 230 V supply. Both use the heating effect of current.

    (a)

    Explain why the lamp glows but the kettle does not.

    [2 marks]
    (b)

    State one use of the heating effect of electric current, other than in a lamp or a kettle.

    [1 mark]
    Answer and see the solution →

  5. Question 15

    4 marks · Normal

    A washing machine has a power rating of 1800 W. It is used for 40 minutes during a wash cycle.

    (a)

    Calculate the total energy transferred by the washing machine in one wash cycle.

    [2 marks]
    (b)

    Suggest one effect on the wash cycle if the heating element had a much lower resistance than normal.

    [2 marks]
    Answer and see the solution →

  6. Question 16

    3 marks · Normal

    Some electrical appliances have double insulation and do not need an earth wire.

    (a)

    Describe what is meant by double insulation.

    [1 mark]
    (b)

    Explain why double insulated appliances do not need an earth wire.

    [2 marks]
    Answer and see the solution →