Question

For making a strong electromagnet, the material of the core should be:
A. Soft iron
B. Steel
C. brass
D. copper

Answer 1

Hint:A current passes through the conductor, and when that current is strong enough, it produces a magnetic field. The magnetic field is ‘conducted or contained' in the ferromagnetic conductor, while the electrical conductor is protected against current leakage through the ferromagnetic device.

Complete answer:
An electromagnet is a magnet that generates its magnetic field using an electric current. Electromagnets are made from wire coiled into a coil. A current flowing through the wire produces a magnetic field that is focused in the hole, which serves as the coil's centre. The magnetic field dissipates when the current is turned off.

The wire turns are frequently twisted around a magnetic core formed of a ferromagnetic or ferrimagnetic material such as iron, which concentrates the magnetic flux and produces a stronger magnet. IRON is used in most cores because it is less expensive than nickel or cobalt, the other two ferromagnetic metals. Mechanical resistance is a secondary reason. In comparison to the brittle “ferrites,” iron is ductile (ceramic ferromagnetic materials).

The soft iron inside the coil becomes a magnet when electricity flows through it, the magnetic field is strengthened. Furthermore, as soon as the current stops flowing, it loses its magnetism. It creates a magnetic field that lasts only a few seconds. The electromagnet may be turned on and off in this manner by turning on and off the electricity.

So, the correct option is A.

Note:The advantage of an electromagnet over a permanent magnet is the ability to vary the magnetic field fast by adjusting the amount of electric current in the winding. An electromagnet, on the other hand, requires a constant supply of electricity to sustain the magnetic field, unlike a permanent magnet, which does not require any power.