(a) What is an electromagnet ? List any two uses.
(b) Draw a labelled diagram to show how an electromagnet is made.
(c) State the purpose of soft iron core used in making an electromagnet.
(d) List two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed.

Explanation

(a) An electromagnet is a solenoid coil with a soft iron core. On passing current through solenoid it behaves as a magnet and on stopping current flow the magnetism is lost.
Electromagnets are used in electric door bell, transformer, electric cranes etc.
(b) A labelled diagram showing how an electromagnetic is made is drawn here :

(c) The purpose of soft iron core used in making an electromagnet is to increase the strength of magnetic field.
(d) Strength of an electromagnet can be increased (i) by winding greater number of turns in solenoid coil and (ii) by increasing the current I flowing through the solenoid coil.