(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.

(a) An electromagnet is a temporary magnet which works when current is passed through it.

Two uses of electromagnets are as follows :

1. In electrical devices such as in loudspeaker, electric bell, and electric motor. 

2. Used by doctors in MRI scanners, and for treating knee pain by using a pulsing electromagnetic field (PEMF).

(b) It works on the magnetic effect of current. It consists of a long coil of insulated copper wire wrapped around a soft iron core that gets magnetized only when the electric current is passed through the coil.

To make an electromagnet, a soft iron rod is taken and an insulated copper wire is wrapped over it. The two ends of the copper wire are connected to the battery for making an electromagnet.

(c) The purpose of soft iron core used in making an electromagnet is its property of losing all its magnetism when the current in the coil is switched off, and gaining all its magnetism when the current in the coil is switched on.

(d) Two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed are as follows:

1. Number of turns in the coil: By increasing the number of turns in the coil, the strength of an electromagnet can be increased.

2. Current flowing through the coil: By increasing the current flowing through the coil, the strength of an electromagnet can be increased.