**Faraday’s Laws of Electromagnetic Induction**

Based on his studies on the phenomenon of electromagnetic induction, Faraday proposed the following two laws.

**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.

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

Rate of change of **magnetic flux = (φ _{2} – φ_{1})/t**

According to Faraday’s second law, the magnitude of induced emf is, e α = (φ_{2} – φ_{1})/t. If dφ is the change in magnetic flux in a time dt, then the above equation can be written as; e α dφ/dt