# A singer uses a loudspeaker on stage to hear their own voice played back. Explain how the loudspeaker produces sound from the electrical signal it receives.

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

## Mark scheme (4 marks)

1. The alternating/oscillating electrical current passes through the coil
2. The coil experiences a force due to the interaction between the magnetic field (from the permanent magnet) and the current-carrying coil
3. As the current alternates, the direction of the force on the coil reverses, causing the coil (and cone) to move back and forth / vibrate
4. The vibrating cone causes compressions and rarefactions in the surrounding air, producing 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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/a-singer-uses-a-loudspeaker-on-11ac5999) · Published by Druglandscape Ltd.