Faraday's law of electromagnetic induction : It states that the induced emf is equal to the rate of change of magnetic flux.
In region PQRS as shown in figure, a uniform magnetic field B which is perpendicular to the plane of paper is directed outwards as shown by dotted lines. In this, a rectangular Ioop of wire KLMN is held is held partially in magnetic field inside the plane of paper with KL = I. If x is the portion on the loop inside the field at instant t, then on moving Ioop with velocity v in plane of paper, the loop area linked with magnetic field changes. with this, an induced emf is set up in the wire which is observed through deflection in galvanometer C which is connected in the loop.
