Question

(a) What do you understand by the term "electromagnetic induction" ? Explain with the help of a diagram.

(b) Name one device which works on the phenomenon of electromagnetic induction.

(c) Describe different ways to induce current in a coil of wire.

Answer 1

(a) The production of electricity from magnetism is known as electromagnetic induction. Let us move a wire AB upward rapidly between the poles of the horseshoe magnet. When the wire is moved up, there is deflection in the galvanometer pointer which shows a current is produced in the wire AB momentarily. Thus, as the wire is moved up through the magnetic field, an electric current is produced in it.



(b) Electric Generator

(c) Different ways to induce current in a coil wire are :

• i) by moving the coil relative to a fixed magnet
• ii) by keeping the coil fixed and moving a magnet relative to it