Michael Faraday demonstrated the reverse effect of Oersted experiment. He explained the possibility of producing emf across the ends of a conductor when the magnetic flux linked with the conductor changes. This was termed as electromagnetic induction. The discovery of this phenomenon brought about a revolution in the field of power generation.

### Faraday’s Laws of electromagnetic induction

Faraday’s laws of induction imply that the emf induced in a coil of N turns is directly related to the rate of change of flux through it,

Here ϕ_{B} is the flux linked with one turn of the coil. If the circuit is closed, a current I = ε/R is set up in it, where R is the resistance of the circuit.

**Faraday proposed the following two laws:**

**Faraday’s First law: **

Whenever the amount of magnetic flux linked with a closed circuit changes, an emf is induced in the circuit. The induced emf lasts so long as the change in magnetic flux continues.

**Faraday’s Second law: **

The magnitude of emf induced in a closed circuit is directly proportional to the rate of change of magnetic flux linked with the circuit.

Let ϕ_{1} be the magnetic flux linked to the coil initially and ϕ_{2} be the magnetic flux linked with the coil after a time t. Then

According to Faraday’s second law, the magnitude of induced emf is,

If dϕ is the change in magnitude flux in a time dt, then the above equation can be written as