# Explain how the generator effect is used in an alternator to produce an alternating current.

> WJEC GCSE Physics (Wales) — 1.9 Electromagnetism · Explain · 4 marks

## Mark scheme (4 marks)

1. A conductor/coil rotates within a magnetic field (or there is relative motion between a conductor and a magnetic field)
2. This relative motion induces a potential difference across the ends of the conductor
3. As the coil rotates, the direction of the induced current reverses / changes direction periodically
4. This continual reversal of current direction at a set frequency produces alternating current

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Physics (Wales)](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/explain-how-the-generator-effect-is-905aacdb) · Published by Druglandscape Ltd.