# A student uses an electric toaster to make toast. The toaster has a power-rating of 900 W. Explain why the toaster cannot transfer all of the electrical energy input as useful energy, and describe what happens to the energy that is not usefully transferred.

> Eduqas GCSE Physics — 1.3 Making use of energy · Explain · 4 marks

## Mark scheme (4 marks)

1. The toaster produces waste energy transfer(s) / not all energy goes to the bread/toast
2. Identifies a named form of waste energy transfer (e.g. heat/thermal energy transferred to the surroundings / light energy)
3. States that energy cannot be created or destroyed / conservation of energy
4. States that efficiency can never reach 1 (100%) because of waste energy transfers / the useful output energy is always less than the total energy input

## Key terms

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

## 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-student-uses-an-electric-toaster-0b9270bd) · Published by Druglandscape Ltd.