# A wind turbine uses the generator effect to produce electricity. As the blades turn, a coil of wire rotates between two permanent magnets. Explain how the generator effect produces a current in the coil, and state two ways the magnitude of the induced potential difference could be increased.

> OCR A-Level Physics B: Advancing Physics (H557) — 4.1 Charge and current · Explain · 5 marks

> Wind turbines generate electricity for thousands of homes. Inside the turbine, rotating coils of wire interact with magnetic fields to produce an electrical output.

## Mark scheme (5 marks)

1. The rotating coil experiences a change in magnetic field (or the wire cuts through magnetic field lines)
2. This induces a potential difference across the ends of the coil
3. Because the coil is part of a complete circuit, a current flows
4. First valid method to increase the induced potential difference — e.g. increase the speed of rotation of the coil
5. Second valid method to increase the induced potential difference — e.g. use stronger permanent magnets / increase the number of turns on the coil

## Key terms

- [generator effect](https://www.gradenine.co.uk/glossary/generator-effect)
- [potential difference](https://www.gradenine.co.uk/glossary/potential-difference)
- [induced](https://www.gradenine.co.uk/glossary/induced)
- [permanent magnet](https://www.gradenine.co.uk/glossary/permanent-magnet)

## Related

- [Revision notes for OCR A-Level Physics B: Advancing Physics (H557)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-wind-turbine-uses-the-generator-97cb0718) · Published by Druglandscape Ltd.