# A wind turbine uses the generator effect to supply electricity to homes in a village. The turbine's rotating coil spins between two permanent magnets. Explain how the generator effect produces a current in the coil and why the current supplied to the homes is alternating.

> OCR A-Level Physics A (H556) — 4.2 Energy, power and resistance · Explain · 5 marks

> Wind turbines are increasingly used to generate electricity. Inside a wind turbine, a coil of wire rotates between two permanent magnets as the blades spin in the wind.

## Mark scheme (5 marks)

1. The rotating coil (conductor) moves relative to the magnetic field / cuts through the 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. As the coil rotates, the direction in which it cuts the field lines reverses (every half turn)
5. This causes the direction of the current to constantly reverse / change direction, producing alternating current

## Key terms

- [generator effect](https://www.gradenine.co.uk/glossary/generator-effect)

## Related

- [Revision notes for OCR A-Level Physics A (H556)](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-79e84e96) · Published by Druglandscape Ltd.