Faraday – One of the most influential scientists and his electromagnetic induction

By Chong LIU,
PhD candidate at Polytechnique Montreal

Because of Faraday’s contribution to physics, electricity can be generated from magnetism, let human society enter the electrical age…

Who is Faraday?

Michael Faraday, one great scientist, was born in Newington Butts, England, on 22 September 1791. His family was poor, he had little formal education and had to educate himself. 1805-1812, he was an apprentice in the George Riebau’s bookshop and read many books. In 1813, he became the assistant employed by Dav and employed as a chemical assistant at the Royal Institution on 1st March 1813. In 1824, he was elected as a fellow of the Royal Society, the next year he was appointed as laboratory chief. In 1933, he was elected as lifetime position of the Rol Institution..

 Source: Wikipedia

Source: Wikipedia

During his seven years apprenticeship, he shown an interest in science, especially in electricity, got the inspiration from the book Conversations on Chemistry by Jane Marcet. In Davy’s tour of the continent in 1813-15, as the scientific assistant and the valet of Davy, Faraday never gave up, even Davy’s wife treated him as a servant. He had access to the scientific elite of Europe, and that stimulated his ideas.

As a physicist, Faraday established the most basic law of electromagnetism called Faraday’s law of electromagnetic induction, and diamagnetism

As a chemist, he discovered benzene and the laws of electrolysis and became the first and foremost Fullerian Professor of Chemistry at the Royal Institution.

As an experimentalist, he conveyed his ideas in clear and simple language.

What is the Faraday’s law of electromagnetic (EM) induction? And how is it invented?

Faraday’s law of electromagnetic induction: the voltage (electricity) will be induced while the magnetic flux changes in the coil.

In Faraday’s diary, he wrote his brilliant idea in 1822: magnetism can induce electricity. He believed in his faith and pursued it.

Faraday carried out a large number of experiments to generate electricity from magnetism. In the experiment, Faraday connected the coil to the galvanometer, plugged the magnet into the coil and turned on the switch. No current was generated. He failed, tried again, and failed again. Ten years past. One day Faraday forgot to turn off the switch, and he pulled out the magnet from the coil. That was the 29th of August, 1831, he succeeded to generate the electricity. Then he proved that changing magnetic flux in the coil induces electricity.

 (Modified from electrical4u.com)

(Modified from electrical4u.com)

The changing intensity of magnetic field around the coil induces electricity (left figure). Keep magnet or coil stationary, moving coil or magnet away and towards other one, the electricity will be generated (right two figures).

  (Captured from youtube.com)

What is the application of EM induction?

The Faraday’s law of electromagnetic induction has wide application, especially nowadays, the electricity is widely used in human activities, including electrical machines, industries and medical field.

·         Electrical transformer;

·         Electrical generator;

·         Induction cooker;

·         Musical instrument et al.

Great achievement comes from interest. Interest will push you yourself to be knowledgeable, to observe and get inspiration and creativity from other things, to pursue your faith and never give up.

The philosopher should be a man willing to listen to every suggestion, but determined to judge for himself. He should not be a respecter of persons, but of things. Truth should be his primary object.
— Michael Faraday