- On August 29 in 1831, British scientist Michael Faraday discovered electromagnetic induction, a seminal breakthrough which laid the groundwork for later researchers such as James Clerk Maxwell, and led to important inventions such as electric motors, transformers, inductors, and generators.
Who was Michael Faraday, and how did he discover electromagnetic induction?
- Michael Faraday is regarded as one of the greatest scientists produced by 19th century England, with pioneering contributions in both chemistry and electromagnetism.
- Born in 1791 into considerable poverty, Faraday did not receive a formal education. He learnt to read and write at Sunday church. Faraday began working at the age of 14 with a bookdealer in London, and discovered his inclination towards science by reading books his employer was rebinding.
- In 1812, Faraday secured an apprenticeship with the legendary chemist Sir Humphry Davy, the inventor of the Davy lamp. At the end of this association, Faraday set out on his own illustrious career as a scientist. The initial years were endowed with success in chemistry; in 1825, Faraday discovered Benzene.
- Faraday’s main interests, however, were electricity and magnetism. Apart from electromagnetic induction, Faraday also discovered diamagnetism, electrolysis, and the effect of magnetism on light.
Faraday’s iron ring experiment
- Faraday wrapped a thick iron ring with two coils of insulated wire, one on each side of the ring. One coil was connected to a battery, and the other to a galvanometer. When the battery circuit was closed, Faraday saw a momentary deflection on the galvanometer. A similar momentary deflection but in the opposite direction was seen when the battery circuit was opened.
- This observation led to the discovery that a change in a magnetic field produces an electromotive force and current in a nearby circuit. This phenomenon, called electromagnetic induction, was later mathematically modelled by James Clerk Maxwell and came to be known as Faraday’s Law.
- The foundation laid by Faraday helped Maxwell further investigate electromagnetic field theory, and the latter’s contribution then significantly influenced 20th century physics.