# A household uses several electrical appliances every day. Explain why the kilowatt-hour is used as the unit of energy for recording domestic energy consumption rather than the joule.

> WJEC GCSE Physics (Wales) — 1.4 Domestic electricity · Explain · 4 marks

> A family receives an electricity bill showing the number of units of energy used each month. Each unit on the bill is one kilowatt-hour.

## Mark scheme (4 marks)

1. The joule is a very small unit (of energy)
2. Domestic appliances transfer large amounts of energy, so the number of joules would be very large / difficult to work with
3. The kilowatt-hour is a larger / more convenient unit for measuring energy at domestic scale
4. The kilowatt-hour links directly to the power-rating of an appliance and the time it is used, making billing straightforward

## Key terms

- [kilowatt-hour](https://www.gradenine.co.uk/glossary/kilowatt-hour)
- [domestic energy consumption](https://www.gradenine.co.uk/glossary/domestic-energy-consumption)

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-household-uses-several-electrical-appliances-9e50a374) · Published by Druglandscape Ltd.