Question

What is the source of magnetism in materials?

Answer 1

Hint: The current in the conductor and the charged particles in the conductor always move in a direction opposite to each other. Iron and nickel are the kinds of materials that are strongly magnetized in the magnetic field. If all the electrons move in the same direction then those materials are said to be strongly magnetized.

Complete answer:
A substance is made up of tiny particles. These tiny particles are known as atoms. An atom contains protons, electrons, and neutrons. A proton is a positively charged particle, electrons are the negatively charged particles and neutrons are neutral, that is they are neither positive nor negative.
The subatomic particle of an electron is responsible for carrying charge inside any substance. The electrons keep moving around the nucleus of the atom and when the electrons keep moving around the nucleus then an electric charge will be generated in the substance and therefore these electrons play the role of magnet in materials.
Magnetic dipole often plays a wide role in generating magnetism in the material. When the electrons revolve around the nucleus then it creates two magnetic poles that are the south pole and north pole and that results in a magnetic dipole.
Materials can also be classified into two types that are paramagnetic, diamagnetic, and ferromagnetic materials
In paramagnetic materials, the atoms have a permanent dipole moment and all the electrons move in the same direction. These materials are feebly magnetized in the magnetic field. Examples are sodium, potassium, etc.
In ferromagnetic materials, the atoms have non-zero dipole moment and these materials are strongly magnetized in the magnetic field. Some examples are iron, cobalt, nickel, etc.
In diamagnetic materials, the atoms have zero dipole moment and they are feebly magnetized in a direction opposite to that of the magnetic field. Some examples are gold, diamond, etc
So from the above information, we can conclude that the movement to electric charges in the substance causes magnetism in the material.

Note: In an atom, if the nucleus has the same number of electrons around it that are moving opposite to each other then those electrons cancel out the effect of each other, and hence no magnetism will be produced in the substance. Earth does not have a uniform magnetic field, it varies from place to place.