GEOLOGY

Detailed explanation-1: -A simple electromagnet consisting of a coil of wire wrapped around an iron core. A core of ferromagnetic material like iron serves to increase the magnetic field created. The strength of magnetic field generated is proportional to the amount of current through the winding.

Detailed explanation-2: -The Electromagnet. If we concentrate the magnetism created by a current carrying wire by wrapping it in a tight coil around an iron core (here a nail), we get an electromagnet: a magnet we can turn on and off!

Detailed explanation-3: -An Electromagnet is a current carrying wire wrapped around an iron core. The magnetic field of the electric current in the wire makes the domains inside the iron core line up, magnetizing the core.

Detailed explanation-4: -An iron core makes a temporary electromagnet. It loses its magnetism as soon as the switch is opened and the current is switched off. A steel core makes a more permanent magnet. It does not lose its magnetism quickly when the current is switched off.

Detailed explanation-5: -D They are temporary magnets. Electromagnets are a special class of magnets with properties such as: The polarity of the magnets can be reversed by reversing the current flow. As long as electric current flows through them, they behave as magnets, i.e. they are temporary magnets and hence can be switched on and off.