CBSE Class 10 Answered

Principle : DC generator

It is based on the principle of production of dynamically (or motionally) induced e.m.f (Electromotive Force). Whenever a conductor cuts magnetic flux, dynamically induced e.m.f. is produced in it according to Faraday's Laws of Electromagnetic Induction. This e.m.f. causes a current to flow if the conductor circuit is closed.

  Hence, the basic essential parts of an electric generator are :

   A magnetic field and

   A conductor or conductors which can so move as to cut the flux.

Principle : A.C. generators or alternators (as they are usually called) operate on the same fundamental principles of electromagnetic induction as D.C. generators.

Alternating voltage may be generated by rotating a coil in the magnetic field or by rotating a magnetic field within a stationary coil. The value of the voltage generated depends on-

1.) the number of turns in the coil.

2.) strength of the field.

 3.) the speed at which the coil or magnetic field rotates.