Electromagnetic Induction – Notes

Introduction to electromagnetic induction
Electricity and magnetism are inter-related and the energies linked with them are also inter- convertible.
Whenever there is relative motion between the magnet and a coil, an electric current is induced in the coil.

Faraday’s law of electromagnetic induction
The area of a plane surface is represented by a vector drawn along the outward normal to the plane surface.
φB=B .A=BA cos⍬
The time rate of change of magnetic flux through a closed coil induces an emf through it.
E=- d øB/dt

Lenz’s law
The polarity of induced emf in a closed loop is such that it tends to produce a current which opposes the change in the magnetic flux that produces it.

Motional electromotive force
Magnetic flux ɸB = BƖx