# Electromagnet class 10 | cbse24

## Electromagnet:

An electromagnet works on the magnetic effect of current. An electric current can be used for making temporary magnets known as electromagnets.
As electromagnet is a magnet having of a long coil of insulated copper wire wrapped around a soft iron core that is magnetised only when electric current is passed through the coil.

Note:-Soft iron is more suitable than steel for cores of electromagnets.

When we pass current through the solenoid, a magnetic field is set up in the space within the solenoid. The ends of the solenoid at which the current in the solenoid seems to flow anticlockwise acts an N-Pole and  other one as S-Pole when the current in the magnetism almost completely due to its low retentivity.

Note:-The high permeability of soft iron increases the field one thousand times.

### Factors affecting the strength of an Electromagnet:-

1. The number of turns in the coil:-If we increase the number of turns in the coil, the strength of electromagnet increase.
2. The current flowing in the coil:-If the current in the coil is increased, the strength of electromagnet increase.
3. The length of air gap between its poles:-If we reduce the length of air gap between the poles of an electromagnet, then its strength increase.

Example:-The air gap between the poles of a bar type electromagnet is quite large, so a bar type electromagnet is not very strong. On the other hand, the air gap between the poles of a U-shaped electromagnet is small, so it is a very strong electromagnet.

## Uses of Electromagnets:-

1. Electromagnets are used in electric bells, loud-speakers and telephone diaphragms.
2. Large electromagnets are used in cranes to lift heavy machinery and bulk quantities of iron and steel.
3. In hospitals, electromagnets are used to remove iron or steel bullets from the human body.
4. Electromagnets are used in Maglev train.

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