The newest 13 of 12 written questions. Open one to see it on the real paper.
State the type of transformer used at power stations to supply power to the electricity network.
See it on the paper →A transformer is connected to a 230 V mains supply. An output of 3.6 V is required. The secondary coil has 720 turns. Calculate the number of turns on the primary coil. number of turns =
See it on the paper →State the change made to the voltage by a step-up transformer.
See it on the paper →A step-down transformer is used near homes. The primary voltage is 30 000 V and the primary coil has 25 000 turns. The secondary coil has 90 turns. Calculate the secondary voltage. secondary voltage = V
See it on the paper →Circle the component which is part of a basic transformer. cell permanent magnet soft‑iron core straight wire
See it on the paper →An ideal transformer has 2500 turns on the primary coil and 400 turns on the secondary coil. There is a voltage of 230 V across the primary coil. Calculate the voltage across the secondary coil. voltage = V
See it on the paper →The current in the secondary coil is 1.6 A. Calculate the current in the primary coil. current = A
See it on the paper →What is the output current?
See it on the paper →The step‑up transformer contains 3000 turns on the primary coil. Calculate the number of turns on the secondary coil. number of turns =
See it on the paper →Explain why electricity is transmitted at a voltage of 132 000 V and not 25 000 V.
See it on the paper →The variable power supply used by the student uses a transformer to reduce the output. The current in the primary coil of the transformer is 10.5 A and the current in the secondary coil is 4.2 A. The primary coil contains 360 turns and the transformer can be assumed to be 100% efficient. Calculate the number of turns i...
See it on the paper →There is a rechargeable electric toothbrush in the bathroom of the house. Fig. 12.2 shows the electric toothbrush and the charger. Fig. 12.2 In the charger, there is a transformer that steps down the voltage from 220 V to 2.4 V. The primary coil of the transformer has 5000 turns. Calculate the number of turns on the se...
See it on the paper →is the output current?
See it on the paper →The correct change of an increase in voltage was generally identified.
— Examiner report, May/June 2025, 0654/42 Q11(c)(i) (Cambridge)
A common issue was with errors in the formula. Candidates that stated the correct formula generally gave the correct value of the secondary voltage of 108 V.
— Examiner report, May/June 2025, 0654/42 Q11(d) (Cambridge)
This calculation proved difficult for some candidates, as they confused the formula and incorrectly arrived at a value of 10.
— Examiner report, February/March 2025, 0654/42 Q10(b)(iii) (Cambridge)
Past papers, syllabus and examiner reports © UCLES (Cambridge University Press & Assessment). Questions are matched to topics from the official syllabus. AssessPro is independent and not endorsed by Cambridge.