# A hairdryer has a plastic casing and is connected to the mains supply using a two-core cable containing a live wire and a neutral wire. Explain why a hairdryer with a plastic casing does not need an earth wire, and explain the role of the fuse inside the hairdryer's plug.

> Eduqas GCSE Physics — 7.4 Domestic uses and safety · Explain · 4 marks

## Mark scheme (4 marks)

1. Plastic is an electrical insulator / does not conduct electricity
2. So the casing cannot become live / there is no risk of electrocution if the casing is touched
3. The fuse melts / breaks the circuit if the current exceeds the fuse rating
4. This protects the appliance / wiring / prevents fire / prevents damage caused by a large current

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE Physics](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-hairdryer-has-a-plastic-casing-fefb3435) · Published by Druglandscape Ltd.