Who discovered electromagnetic induction?
Quick answer
English scientist Michael Faraday discovered electromagnetic induction in 1831. He showed that moving a magnet near a coil of wire, or changing a magnetic field, creates an electric current. This principle powers almost all the world’s electric generators and transformers.
Faraday’s experiments
In August 1831, Faraday wrapped two coils of wire around an iron ring. When he switched on a current in one coil, a brief current appeared in the other. Weeks later, he showed that pushing a magnet in and out of a coil also produced a current. The key was change: a steady magnet did nothing, but a moving one created electricity.
American scientist Joseph Henry discovered induction independently at about the same time, but Faraday published first.
Faraday’s law, simply
The faster the magnetic field changes, and the more turns of wire in the coil, the bigger the voltage produced.
Where induction is used today
| Device | How induction helps |
|---|---|
| Power station generators | Spinning magnets and coils produce electricity |
| Transformers | Change voltage for power lines and chargers |
| Wireless phone charging | Coils in the pad and phone transfer energy |
| Induction cooktops | Changing fields heat metal pans directly |
| Electric guitar pickups | Vibrating strings change a magnetic field |
| Wind turbines | Turn wind into electricity |
Who was Michael Faraday?
Faraday (1791–1867) came from a poor family and had little formal schooling. He worked as a bookbinder’s apprentice, reading the books he bound. After attending lectures by chemist Humphry Davy, he became Davy’s assistant at the Royal Institution in London and went on to become one of history’s greatest experimental scientists.
His other achievements include:
- Building the first electric motor (1821)
- The Faraday cage, which blocks electric fields
- Discovering benzene
- Starting the Royal Institution Christmas Lectures for young people, still held today
The unit of electrical capacitance, the farad, is named after him.
Electricity is the flow of electrons; see which part of an atom has a negative charge. Resistance is measured in ohms.
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