360Faraday discovers how to make electricity from magnetism
On 29 August 1831, Michael Faraday showed in London that a changing magnetic field can create an electric current. This discovery, electromagnetic induction, is the principle behind every power-station generator and transformer today. Within weeks he built the first electric generator, a copper disc spinning between the poles of a magnet.
In 1820, scientists learned that an electric current creates magnetism. Michael Faraday, a self-taught scientist at the Royal Institution in London, wanted to know whether magnetism could create electricity.
On 29 August 1831, he wound two coils of wire around an iron ring. When he switched on a current in one coil, a needle connected to the other coil flicked, then fell back. It moved again when he switched the current off. A changing magnetic field had made a current flow.
Over the following weeks, he showed that moving a magnet in and out of a coil also produced a current. In October 1831, he built a generator: a copper disc turning between the poles of a magnet, producing a steady current.
This principle, electromagnetic induction, made electricity practical. It is how generators in power stations turn motion into electricity, and how transformers change voltages so power can travel across countries.
Faraday, the son of a blacksmith, became one of the most celebrated scientists of his century. The farad, a unit of electrical capacitance, is named after him.
- 1820
- Ørsted shows that electric current creates magnetism
- 29 August 1831
- Faraday's induction ring experiment
- October 1831
- Faraday builds the first generator
- 1882
- Edison's first central power station opens in London
Sources: Royal Institution · Britannica · Institution of Engineering and Technology.