Electromagnetic Induction

What is Electromagnetic Induction?

In Electromagnetic induction a voltage or an electromotive force is produced due to a change in the magnetic field. This phenomenon was discovered by Michael Faraday in 1830s. Now let us see how this electromagnetic induction can be generated.The Electromagnetic Induction can be generated in two ways. The first way is an electric conductor is placed in moving magnetic field and the second way is the conductor is moving in a static magnetic field.


Faraday discovered the Electromagnetic Induction when he moved a magnetic bar through a coil and noticed a change in the voltage in the circuit. After this discovery he started considering the factors which can affect the Electromagnetic Induction like the strength of the magnet, number of coils etc.

The number of turns in the coil is directly proportional to the voltage induced and the changing magnetic field and also the relative speed of the magnet and the coil also influences the voltage in the circuit. Therefore the total voltage induced in an electromagnetic induction is given by the following equation.

                               e = N × dΦdt

where e is the induced voltage in volts

t is time in seconds

N is number of turns in the coil

Φ is magnetic flux measured in Webers

Faraday’s law of Electromagnetic Induction

Faraday proposed two laws on electromagnetic Induction known as the first law and the second law.

First Law: The first law says that if a conductor is placed in a varying magnetic field then EMF is induced and this is called as induced EMF and if the conductor is closed then the current flows through it.

Second law: The second law states that the magnitude of the induced EMF is equal to the rate of change of flux linkages.

Lenz’s law of Electromagnetic Induction

Lenz law of Electromagnetic induction states that according to Faraday’s law if the EMF is induced then the direction of induced EMF is such that it opposes the cause of its production. The Equation formed according to this law is:

E = -N (dΦ/ dt)   (volts)

Applications of Electromagnetic Induction

The electromagnetic induction has a very wide range of applications. Most of the things which we use now require electricity. The Electromagnetic Induction is the biggest contributor of the production of electricity. We cannot imagine the production of electricity without Electromagnetic induction. The biggest application of Electromagnetic Induction includes AC Generator, Electrical transformers, Magnetic flow meters etc.

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