# A washing machine is connected to the mains electricity supply using a three-core cable. The cable contains a live wire, a neutral wire, and an earth wire. Explain the role of the earth wire and the fuse in protecting a user if the live wire accidentally touches the metal casing of the washing machine.

> Cambridge International IGCSE Physics (0625) — 4.4 Electrical safety · Explain · 4 marks

## Mark scheme (4 marks)

1. The earth wire connects the metal casing to the ground (earth), providing a low-resistance path for current to flow.
2. A large current flows through the earth wire when the live wire touches the casing.
3. The large current causes the fuse wire to heat up and melt (blow).
4. The circuit is broken, disconnecting the appliance from the live supply and protecting the user from electrocution.

## Key terms

- [earth wire](https://www.gradenine.co.uk/glossary/earth-wire)
- [live wire](https://www.gradenine.co.uk/glossary/live-wire)
- [fuse](https://www.gradenine.co.uk/glossary/fuse)

## Related

- [Revision notes for Cambridge International IGCSE Physics (0625)](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-washing-machine-is-connected-to-940e83e8) · Published by Druglandscape Ltd.