# A consumer receives an electricity bill showing that their household used 350 kilowatt-hours of electrical energy last month. The bill also states that the cost per kilowatt-hour is 28p. Explain what the term 'power-rating' means for a household appliance, and describe how the power-rating of an appliance and the time it is used both affect the total number of kilowatt-hours shown on an electricity bill.

> Eduqas GCSE Physics — 1.4 Domestic electricity · Explain · 4 marks

## Mark scheme (4 marks)

1. Power-rating is the maximum rate of energy transfer of an appliance
2. A higher power-rating means more kilowatt-hours are used (for the same time of use)
3. The longer an appliance is used, the more kilowatt-hours are used
4. The number of kilowatt-hours depends on both power-rating (in kilowatts) and time (in hours) — greater values of either increase the total

## Key terms

- [power-rating](https://www.gradenine.co.uk/glossary/power-rating)
- [kilowatt-hour](https://www.gradenine.co.uk/glossary/kilowatt-hour)

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-consumer-receives-an-electricity-bill-f558301f) · Published by Druglandscape Ltd.