Question

(a) What is an electromagnet? Draw a labelled diagram to show the making of a simple electromagnet.
​(b) State three factors on which the strength of an electromagnet depends. How does the strength of electromagnet depend on these factors?

Answer 1

(a) An electromagnet is a device used to generate a magnetic field with the help of an electric current. Unlike permanent magnets, the strength of an electromagnet can be increased by increasing the amount of current flow through them.



(b) Three factors affecting the strength of an electromagnet are as follows:

(i) Strength of the current passing through the core of the magnet.
(ii) The number of tunes of the wire in the core.
(iii) The material of the core

When the current flowing through the core is increased, the magnetic field produced by the current increases, therefore the strength of the electromagnet increases.

Increase in the number of turns of the wire of core also increases the magnetic field, hence the strength of the electromagnet increases by increasing the number of turns in the wire of the coil.

The metal inside the coil magnifies the field created by it. Changing the metal core for a different metal will make the electromagnet stronger or weaker.