# A current-carrying wire is held at right angles to a uniform magnetic field between two permanent magnets. Explain why the wire experiences a force, and describe two ways in which the magnitude of this force could be increased.

> Edexcel A-Level Physics (9PH0) — 12.1 Newtonian gravity · Explain · 5 marks

> A straight conducting wire carries a current of 2 A and is placed perpendicular to the magnetic field between the poles of two permanent magnets. The wire is observed to move.

## Mark scheme (5 marks)

1. The current in the wire produces a magnetic field around the wire
2. This magnetic field interacts with the magnetic field of the permanent magnets
3. The resultant force on the wire is perpendicular to both the current direction and the magnetic field direction
4. The force can be increased by increasing the current through the wire
5. The force can be increased by increasing the magnetic flux density of the field (e.g. using stronger magnets)

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Physics (9PH0)](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-current-carrying-wire-is-held-at-006720a7) · Published by Druglandscape Ltd.