State and explain Faraday's law of electromagnetic induction.

Explanation

Statement: "The magnitude of the induced emf in a circuit is equal to the time rate of change of magnetic flux through the circuit."
Mathematically, the Induced emf is given by
`epsilon=(dPhi_B)/(dt)`..(1)
The negative sign indicates the direction of e and hence the direction of current in a closed loop.
In the case of a closely wound coil of n turns, change of flux associated with each turn, is the same. Therefore, the expression for the total induced emf is given by
`epsilon=-N (dPhi_B)/(dt)`..(2)
The induced emf can be increased by increasing the number of turns n of a closed coil.