# A student wraps a length of wire into a coil to make a solenoid and connects it to a power supply. She then investigates ways to increase the strength of the magnetic field produced by the solenoid. Explain how the student could increase the strength of the magnetic field produced by the solenoid, and explain why each method works.

> OCR A-Level Physics B: Advancing Physics (H557) — 4.3 Electrical circuits · Explain · 5 marks

> A solenoid is a wire wrapped into the shape of a coil. It produces a strong and uniform magnetic field inside it. The strength of this field depends on several factors.

## Mark scheme (5 marks)

1. Increase the current through the solenoid
2. A greater current produces a stronger magnetic field around the wire / more field lines are produced
3. Increase the number of turns (coils) of wire
4. More turns cause more individual magnetic fields to combine / align, producing a stronger overall field
5. Insert an iron core into the centre of the solenoid

## Key terms

- [solenoid](https://www.gradenine.co.uk/glossary/solenoid)
- [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 "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-student-wraps-a-length-of-536be3b0) · Published by Druglandscape Ltd.