The transformer: past paper questions
Real questions on the transformer
The newest 20 of 24 written questions. Open one to see it on the real paper.
- 0972/41 · May/June 2026 · Q10c(ii)[2]
(ii) A transformer in the power station steps up the voltage from 25000V to 400 000V. The transformer has 240 turns on the primary coil. Calculate the number of turns on the secondary coil of the transformer. Number turns .......... .......... .......... [2]
See it on the paper → - 0972/31 · October/November 2025 · Q8b[3]
The television uses a transformer. The input voltage (V p ) to the transformer is 120 V. The number of turns (N p ) on the input coil is 560. The number of turns (N s ) on the output coil is 70. Calculate the output voltage (V s ) of the transformer. output voltage = V
See it on the paper → - 0972/31 · May/June 2025 · Q9c[3]
The router uses a transformer. The number of turns N p on the primary coil of the transformer is 3600. The primary voltage V p to the transformer is 240 V. The secondary voltage V s of the transformer is 12 V. Calculate the number of turns N s on the secondary coil of the transformer. number of turns on secondary coil...
See it on the paper → - 0972/41 · May/June 2025 · Q8c(i)[3]
Explain the advantages of transmitting electricity at high voltages. (i)
See it on the paper → - 0972/41 · May/June 2025 · Q8c(ii)[2]
A power station generates electricity at 25 000 V. A transformer steps up the voltage to 300 000 V. The primary coil of the step-up transformer has 450 turns. Calculate the number of turns N s on the secondary coil of the transformer. N s =
See it on the paper → - 0972/31 · October/November 2024 · Q10c[3]
The power supply includes a transformer. The voltage (V p ) across the primary coil of the transformer is 228 V. The voltage (V s ) across the secondary coil of the transformer is 12 V. The number of turns on the primary coil (N p ) is 760. Calculate the number of turns (N s ) on the secondary coil. number of turns on...
See it on the paper → - 0972/31 · May/June 2024 · Q9b(i)[3]
Calculate the output voltage V s of the secondary coil. secondary coil output voltage V s = V
See it on the paper → - 0972/31 · May/June 2023 · Q10b[3]
Fig. 10.2 shows the symbol for a transformer. The primary coil is connected to a voltage of 180 V a.c. primary voltage V p = 180 V a.c. primary coil 4800 turns secondary coil 200 turns secondary voltage V s Fig. 10.2 Calculate the secondary voltage V s for the transformer. V s = V
See it on the paper → - 0972/32 · May/June 2023 · Q9b(i)[1]
State the name of this type of transformer.
See it on the paper → - 0972/32 · May/June 2023 · Q9b(ii)[4]
Describe the construction of this transformer. You may include a labelled diagram.
See it on the paper → - 0972/41 · May/June 2023 · Q8a[4]
Explain the principle of operation of a simple iron-cored transformer.
See it on the paper → - 0972/31 · October/November 2022 · Q9b[3]
The mains input (primary) potential difference (p.d.) to the transformer is 230 V a.c. The number of turns on the input (primary) coil is 314. The number of turns on the output (secondary) coil is 150. Calculate the output (secondary) p.d. from the transformer. output p.d. = V
See it on the paper → - 0972/31 · October/November 2022 · Q9c(i)[1]
State a suitable material for the core of the transformer.
See it on the paper → - 0972/31 · October/November 2022 · Q9c(ii)[1]
State a suitable material for the primary and secondary coils of the transformer.
See it on the paper → - 0972/31 · October/November 2022 · Q9c(iii)[1]
Explain how Fig. 9.2 shows a step-down transformer.
See it on the paper → - 0972/31 · May/June 2022 · Q10b[3]
The electric circuit for the microwave oven includes a transformer. The voltage to the primary coil of the transformer V p is 240 V. The number of turns on the primary coil N p is 70. The number of turns on the secondary coil N s is 560. Calculate the secondary voltage V s for the transformer. V s = V Permission to rep...
See it on the paper → - 0972/41 · May/June 2021 · Q7b[3]
Terminals X and Y are connected to the primary coil of a transformer. State and explain what happens in the transformer as the student turns the handle of the a.c. generator.
See it on the paper → - 0972/31 · October/November 2020 · Q12b[3]
Another circuit includes a transformer. The input voltage of the transformer is 120 V a.c. The input coil has 480 turns of wire and the output coil has 60 turns of wire. Calculate the output voltage of the transformer. output voltage = V
See it on the paper → - 0972/42 · May/June 2020 · Q7a(i)[3]
Complete and label Fig. 7.1 to show the transformer connected to the supply and the output from the transformer.
See it on the paper → - 0972/42 · May/June 2020 · Q7a(ii)[2]
Explain the function of the piece of iron in the transformer.
See it on the paper →
What examiners said
The majority of candidates scored full credit for calculating the number of turns on the secondary coil as 180. Many candidates scored partial credit for correctly substituting into a correct form of the equation. The most common error was using an incorrect rearrangement of the transformer equation. Many candidates thought that Ns Vp = Np Vs is a correct form of the transformer equation.
— Examiner report, May/June 2025, 0972/31 Q9(c) (Cambridge)
Many candidates stated that there is less energy/power loss with high-voltage transmission. Some candidates explained this by stating the power loss equation, P = I2R. Other candidates stated that high-voltage transmission meant a lower current and explained that this allowed cost savings because thinner wires could be used. Contradictory statements about resistance or a change in power transmitte...
— Examiner report, May/June 2025, 0972/41 Q8(c)(i) (Cambridge)
Many candidates correctly recalled and used the equation relating turns ratio to voltage ratio and gained full credit here. Weaker candidates sometimes had difficulty rearranging the equation or deciding which values to substitute for each term in the equation.
— Examiner report, May/June 2025, 0972/41 Q8(c)(ii) (Cambridge)
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