# A wind turbine generates electricity for a remote farmhouse. The turbine contains a coil of wire that rotates between two permanent magnets. Explain how the rotating coil produces an alternating current that can be used to power electrical appliances in the farmhouse.

> OCR A-Level Physics B: Advancing Physics (H557) — 4.2 Energy, power and resistance · Explain · 5 marks

> Wind turbines are used in rural areas to generate electricity. Inside each turbine, a coil of wire is made to spin by the turning blades.

## Mark scheme (5 marks)

1. The rotating coil moves relative to (cuts through) the magnetic field
2. This induces a potential difference across the ends of the coil (generator effect)
3. A current flows because the coil is part of a complete circuit
4. As the coil rotates, the direction of the induced current reverses repeatedly / continually changes direction
5. This produces alternating current (AC), which changes direction at a set frequency / matches the rotation frequency of the coil

## Key terms

- [alternating current](https://www.gradenine.co.uk/glossary/alternating-current)

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-wind-turbine-generates-electricity-for-eaee7f6c) · Published by Druglandscape Ltd.