Question

Q5 What is an electromagnet ? How is it different from a permanent magnet ? State two uses of electromagnet.

Answer 1

If a core of iron is wounded by a wire in the form of solenoid, if current is passed through that wire, then it acts as a magnet. This magnet which which works with the use of electricity is called electromagnet. 

Electromagnet is  different from a permanent magnet. An electromagnet can be demagnetized while a permanent magnet cannot be demagnetized. The direction of an electromagnet can be changed but for a permanent magnet cannot be changed.

Uses of electromagnet:
1. It produces a greater magnetic field
2. The strength  of an electromagnet can be increased.

Hope my answer helps you.

Answer 2

An electromagnet is a magnet which is made by passing electric current in a coil wound around a piece of soft iron .

The differences between permanent magnet and electromagnet are as follows :-

⇒ The permanent magnet does not have electric current flow through it.

⇒ Electromagnets are made by passing electric current through it.

⇒ The strength of the magnetic field in permanent magnets cannot be changed.

⇒ The strength of the electromagnets can be changed by changing the amount of current in the magnet.

⇒ The direction of the magnetic field cannot be changed.

⇒ The direction of magnetic field can be changed in electromagnets.

⇒ The polarity of permanent magnets cannot be changed.

⇒ The polarity of the electromagnets can be changed.

⇒ The permanent magnet is generally made of hard iron.

⇒ The electromagnets are generally made of soft iron.

Two uses are :

• Used in doorbells

• Used in MRI machines .