# An engineer is designing an electromagnet to lift scrap metal in a recycling yard. Describe how the strength of the magnetic field produced by the electromagnet could be increased. Give four different ways.

> OCR A-Level Physics B: Advancing Physics (H557) — 4.1 Charge and current · Describe · 5 marks

> An electromagnet consists of a solenoid with an iron core. The recycling yard needs a stronger electromagnet to lift heavier loads of scrap metal.

## Mark scheme (5 marks)

1. Increase the size (magnitude) of the current through the coil
2. Increase the number of turns (coils) of wire
3. Use an iron core (rather than air or a non-magnetic material) / keep the iron core
4. Increase the cross-sectional area of the coil
5. Increase the length of the coil (while keeping the same number of turns, i.e. pack turns more densely, OR explicitly state increasing coil length as a separate factor)

## Key terms

- [electromagnet](https://www.gradenine.co.uk/glossary/electromagnet)
- [magnetic field](https://www.gradenine.co.uk/glossary/magnetic-field)

## Related

- [Revision notes for OCR A-Level Physics B: Advancing Physics (H557)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/an-engineer-is-designing-an-electromagnet-86197837) · Published by Druglandscape Ltd.