Question

What is an electromagnet ? Name two factors on which the strength of magnetic field of an electromagnet depends and state how does it depend on the factors stated by you.

Answer 1

If a soft iron bar is placed inside the solenoid, and the current switched on, the iron bar becomes temporarily magnetized. This is the principle of the electromagnet.
The strength of an electromagnet depends on:

• The strength of the current passing through the coil, the greater the current, the greater the strength. This because the current increases there is more flow of electrons which in turn increases the magnetic field around it.
• The number of turns in the coils, the greater the number of coils, the greater the strength. This is because more the number of coils, more uniformity is obtained in the magnetic field and hence it is more stronger.
• Whether the core is made up of a soft or hard magnetic material. Soft iron core magnetizes more quickly than hard magnetic materials like steel.