# A maglev train uses powerful electromagnets beneath the train carriage to levitate it above the track. Explain how the electromagnets are made and how changing the current in them affects the force they exert on the track.

> OCR A-Level Physics B: Advancing Physics (H557) — 4.2 Energy, power and resistance · Explain · 5 marks

> Maglev trains have no wheels and do not touch the track. Instead, electromagnets on the underside of the train interact with the track to produce a lifting force, allowing the train to float and move with very little friction.

## Mark scheme (5 marks)

1. An electromagnet is made from a solenoid (coil of wire) with an iron core
2. When current flows through the coil/wire, a magnetic field is generated
3. The iron core increases the strength of the magnetic field
4. Increasing the current increases the strength of the magnetic field
5. A stronger magnetic field produces a greater force on the track / increasing current increases the lifting force

## Key terms

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

## 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-maglev-train-uses-powerful-electromagnets-bd8633eb) · Published by Druglandscape Ltd.