# A rescue team uses an electric motor to winch injured climbers up a cliff face. The motor contains a coil of wire that rotates between two permanent magnets. Explain how the motor produces a continuous rotation.

> OCR A-Level Physics A (H556) — 4.3 Electrical circuits · Explain · 5 marks

> An electric motor converts electrical energy into kinetic energy by making use of the force experienced by a current-carrying wire placed in a magnetic field.

## Mark scheme (5 marks)

1. A current flows through the coil of wire (in the magnetic field)
2. The two sides of the coil that are perpendicular to the magnetic field each experience a force
3. The forces on the two opposite sides of the coil act in opposite directions
4. These opposing forces cause the coil to rotate
5. Fleming's Left-Hand Rule can be used to determine the direction of the force / rotation

## Key terms

- [electric motor](https://www.gradenine.co.uk/glossary/electric-motor)

## Related

- [Revision notes for OCR A-Level Physics A (H556)](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-rescue-team-uses-an-electric-ed84a7cb) · Published by Druglandscape Ltd.