Faraday’s Law of Electromagnetic Induction
Michael Faraday discovered the principle of electromagnetic induction. In 1831, Michael Faraday in his famous induction coil experiment discovered the principle of an electric current causing a second electric current. This experiment is one of the few real experiments in the history of science and every student of physics is familiar with it.
In this experiment, Faraday wrapped two copper wires on opposite sides of an iron plate. Based on his understanding of electricity, he expected that when an electric current passed through a wire, a kind of wave would pass through the shell and cause some electrical effects on the opposite side. Faraday connected one wire to the galvanometer and observed the galvanometer while connecting the other wire to the battery. He observed a transient current which Faraday called a wave of electricity. Then when he separated the wire from the battery, the needle of the galvanometer started moving in an upward direction. He was surprised at this. He discovered that the inductance is caused by changes in the magnetic flux that occurs when the battery is connected or disconnected. He explained the relationship of induction with lines of force. However, many scientists of that time rejected his theoretical ideas. The main reason for this was that these ideas were not explained mathematically. James Clerk Maxwell used Faraday’s theories as the basis for his quantitative electromagnetic theory.