GEOLOGY

Detailed explanation-1: -Electromagnets can be turned on or off and their strength can be changed by controlling the electric current. An electromagnet is a solenoid wrapped around a bar of iron or other ferromagnetic material. It is stronger if there are more turns in the coil of wire or there is more current flowing through it.

Detailed explanation-2: -An electropermanent magnet or EPM is a type of permanent magnet in which the external magnetic field can be switched on or off by a pulse of electric current in a wire winding around part of the magnet.

Detailed explanation-3: -A relay is an electromagnetic switch operated by a relatively small electric current that can turn on or off a much larger electric current. The heart of a relay is an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it).

Detailed explanation-4: -An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The poles of an electromagnet can even be reversed by reversing the flow of electricity.

Detailed explanation-5: -An electromagnet loses its magnetism when the current flowing through its coil is stopped.