(i) What is an electromagnet? What does it consist of?
(ii) Name one material in each case which is used to make a :
- Permanent magnet.
- Temporary magnet.
(iii) Describe an activity to show how you can make on electromagnet in your school laboratory.
(i) When we magnetise a piece of magnetic material such as soft iron by keeping it inside
a coil and then passing current through it, the magnet so formed is called electromagnet.
(ii)
- Steel is used to make permanent magnet.
- Soft iron is used to make temporary magnets.
(iii) Take a coil of wire having N number of turns and then wrap it around a soft iron core. Connect the end of the wire with a battery and plug key and then let current pass through the coil, bring a compass near the coil. It will be observed that compass needle shows deflection. This shows that the coil will have a magnetic field of its own. The magnet so formed is called an electromagnet.