0654.P4.4.01 — Describe the heating effect of current: past paper questions

Real questions on 0654.p4.4.01 — describe the heating effect of current

The newest 6 of 6 written questions. Open one to see it on the real paper.

1. 0654/31 · October/November 2025 · Q9d[2]

   An alloy of lead and tin is used to make fuse wire. The alloy has a melting point of 200 °C. A fuse contains fuse wire and is used to protect electrical devices in electrical circuits. Describe how the fuse protects the electrical circuit from the heating effect of an electric current.

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2. 0654/43 · October/November 2024 · Q3b[4]

   The student places the thermistor into hot water. The student records the values shown by the ammeter and the voltmeter as the temperature of the thermistor increases. Describe how the power output of the thermistor changes as the temperature of the thermistor increases.

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3. 0654/42 · February/March 2023 · Q9a[3]

   Fig. 9.1 shows a simple circuit containing a heater and a thermistor. heater thermistor Fig. 9.1 Use Fig. 9.1 to explain how increasing the temperature of the thermistor changes the power output of the heater.

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4. 0654/42 · February/March 2023 · Q9b[3]

   Fig. 9.2 shows an electric kettle. Fig. 9.2 The kettle has a power rating of 3000 W. It takes 336 kJ of energy to heat some water from room temperature to 100 °C. Calculate the time it will take for the kettle to heat the water from room temperature to 100 °C. time = s

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5. 0654/21 · October/November 2019 · Q38[1]

   Why is the extension block now dangerous?

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6. 0654/22 · October/November 2019 · Q38[1]

   is the extension block now dangerous?

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What examiners said

Candidates generally understood the effect of resistance on current and the resultant power output. Some candidates described an increase in temperature of the thermistor leading to an increase in resistance rather than a decrease.

— Examiner report, February/March 2023, 0654/42 Q9(a) (Cambridge)

The conversion of kJ to J proved troublesome for some candidates. Candidates should practise the conversion of units. A common error was to rearrange the formula incorrectly and divide the energy by the power giving a value of 8.9 s.

— Examiner report, February/March 2023, 0654/42 Q9(b) (Cambridge)

Here almost one in three thought that the fuse protects the individual appliances from overheating, rather than the cable.

— Examiner report, October/November 2019, 0654/21 Q38 (Cambridge)