# A student plugs a metal-cased electric kettle into a mains socket. Explain why a fuse is used in the plug of the kettle and describe what happens inside the fuse if a fault causes a very large current to flow.

> AQA GCSE Physics (8463) — 4.2.3 Domestic uses and safety · Explain · 4 marks

## Mark scheme (4 marks)

1. The fuse contains a thin wire (fuse wire) that melts / breaks when the current exceeds a safe level
2. This breaks / disconnects the circuit (stopping current from flowing)
3. This prevents the appliance / wiring / cable from overheating (which could cause a fire)
4. The large current causes the fuse wire to heat up enough to melt (because the heating effect of the current is large)

## Key terms

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

## Related

- [Revision notes for AQA GCSE Physics (8463)](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-student-plugs-a-metal-cased-electric-e3e740b9) · Published by Druglandscape Ltd.