Question

What should be the properties of the core of electromagnets?
1. high permeability and low retentivity
2. low permeability and low retentivity
3. ​high permeability and high retentivity
4. low permeability and high retentivity

Answer 1

Correct Answer - Option 1 : high permeability and low retentivity

CONCEPT:

Electromagnet:

• An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
• Electromagnets usually consist of wire wounds into a coil.
• The magnetism of the electromagnets can be increased by placing a soft iron rod inside the solenoid.
• The core of electromagnets is made of ferromagnetic materials which have high permeability and low retentivity.
• Electromagnets are used in electric bells, loudspeakers, and telephone diaphragms.
• Giant electromagnets are used in cranes to lift machinery, and bulk quantities of iron and steel.

EXPLANATION:

• The magnetism of the electromagnets can be increased by placing a soft iron rod inside the solenoid.
• The core of electromagnets is made of ferromagnetic materials which have high permeability and low retentivity. Hence, option 1 is correct.