# A loudspeaker is connected to an audio amplifier and used to play music. Explain how the loudspeaker converts the oscillating electrical signal from the amplifier into sound waves that can be heard.

> Eduqas GCSE Physics — 8.4 Microphones, speakers, oscillating currents in detection · Explain · 4 marks

## Mark scheme (4 marks)

1. The oscillating electrical current passes through the coil (voice coil) in the loudspeaker
2. The coil is situated in a magnetic field, so the changing current causes a force on the coil / the coil experiences a changing magnetic force
3. The coil (and attached cone/diaphragm) vibrates / moves back and forth
4. The vibrating cone creates compressions and rarefactions in the surrounding air, producing sound waves

## Key terms

- [oscillating electrical signal](https://www.gradenine.co.uk/glossary/oscillating-electrical-signal)
- [sound waves](https://www.gradenine.co.uk/glossary/sound-waves)

## Related

- [Revision notes for Eduqas GCSE 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-loudspeaker-is-connected-to-an-8d94bf65) · Published by Druglandscape Ltd.