Electromagnetic Induction

Whenever the magnetic flux linked with a closed circuit changes, an emf is induced in the circuit, called induced e.m.f. This phenomenon is called electromagnetic induction. The resulting current by electromagnetic induction is called induced current.

Faraday’s laws of electromagnetic induction or principle of electromagnetic induction

This law was propounded by an English physicist named Michael Faraday in 1831 AD. It is also called the principle of generators. It states that: -

1. Whenever the magnetic flux is linked with a closed circuit changes, an emf is induced in the circuit.
2. The induced e.m.f. lasts as long as the change in the magnetic flux continues in the circuit.
3. The magnitude of the induced e.m.f. is directly proportional to the rate of change of magnetic flux.

∴ Induced e.m.f. \(\propto\) Rate of change of magnetic flux

Generator or dynamo

Electrical generators or dynamo are the machines used to convert mechanical energy into electrical energy. They are based on the principle of electromagnetic induction. A dynamo is used to induce current in fewer amounts and a generator is used to induce electric current in large scale.

It should be noted that the name generator is actually a misnomer, as no energy is being generated by it but is only converted from one form to another. A generator or dynamo converts kinetic energy into electrical energy.