# A bicycle dynamo contains a permanent magnet that spins close to a coil of wire. As a cyclist pedals faster, the dynamo produces a larger voltage. Explain why spinning the magnet faster causes a larger voltage to be induced in the coil.

> Eduqas GCSE Physics — 8.3 Induced potential and transformers · Explain · 4 marks

## Mark scheme (4 marks)

1. Spinning magnet produces a changing magnetic field (through the coil)
2. A changing magnetic field induces a potential difference (voltage) in the coil
3. Spinning faster means the magnetic field changes more rapidly / the rate of change of the magnetic field is greater
4. A greater rate of change of magnetic field induces a larger potential difference / voltage

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