# A student moves a bar magnet into a coil of wire connected to a sensitive ammeter. The ammeter needle deflects, showing that a current has been induced. Explain why a current is induced in the coil when the magnet moves into it, and describe TWO ways the student could increase the size of the induced current.

> Eduqas A-Level Physics — 4.5 Electromagnetic induction · Explain · 5 marks

> A bar magnet is pushed into a coil of wire. The coil is connected to a sensitive ammeter, which shows a reading when the magnet moves.

## Mark scheme (5 marks)

1. Moving the magnet into the coil causes the magnetic field through the coil to change (the magnetic flux through the coil changes / the number of magnetic field lines through the coil increases)
2. A changing magnetic field induces a voltage (e.m.f.) in the coil
3. The induced voltage drives a current around the circuit (because the circuit is complete)
4. First valid method to increase the induced current: move the magnet faster / increase the speed of the magnet
5. Second valid method to increase the induced current: use a stronger magnet OR increase the number of turns on the coil

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-moves-a-bar-magnet-c3c706ab) · Published by Druglandscape Ltd.