What is Magnetism

What is Magnetism

A material that generates a magnetic field is known as a magnet. Magnetism is defined as the force produced by charged particles (electrons) of a magnet. In simpler terms, a magnetic substance, for example iron, is attracted by a magnet with the force of magnetism. The force generated can be either attractive or repulsive, depending upon the alignment of the charged particles.

The magnetic effect of a magnet is strongest at the ends (poles); each magnet, irrespective of the size, has two poles - the north pole and the south pole. Conventionally, it is studied that the magnetic field leaves the north pole and enters the south pole. A magnet is called dipole as it possesses two ends that act differently; opposite poles attract, whereas like poles repel each other. An electromagnet is a magnet that requires electricity to generate a magnetic field. Magnets, due to its specific properties, are used in electrical appliances, compasses, industrial magnets, printing magnets, construction works, as magnetic strips in cards, magnetic bracelets, magnetic therapy and several other domains.

How Does Magnetism Work

Every charged particle produces a magnetic filed when it moves. Hence, an electron that spins around the nucleus also generates magnetic field around it. The difference between a magnet and other substance is that in the former case, all the electrons move in the same direction, thus producing a static magnetic field around the magnet. In case of other substances, the electrons spin randomly, hence dispersing the magnetic field in different directions. In such a condition, there is no profound magnetic effect.

Based on the configuration of electrons in the material, magnetic behaviors are classified into several types. One of the most important magnetic behaviors is ferromagnetism; it is the property of a material that remains magnetic, even after the removal of a magnet. Ferromagnetic mechanism is used for creating permanent magnets, for example, magnets used in refrigerators. In the process of making a magnet, a ferromagnetic material is heated first and cooled gradually under a strong magnetic field. As the material cools down, the electrons are forced to align in a particular direction, resulting in a permanent magnet.

Diamagnetism is a type of magnetism exhibited by materials; a diamagnetic material produces an opposite magnetic field when an external magnetic field is applied on the material. Example of diamagnetic materials include copper, gold and mercury. Paramagnetism is more or less similar to diamagnetism; a paramagnetic material is attracted to a magnetic field and generates its own magnetic field in the presence of an external magnetic field. Examples of materials that exhibit paramagnetism are uranium, iron oxide and platinum. In addition, there are other magnetic behaviors such as spin glass (irregular magnetic fields) and superparamagnetism (contains minute ferromagnetic clusters).

The planet Earth also exhibits magnetism, which is referred to as Earth's magnetic field or external magnetic field. When a magnet is suspended in the Northern Hemisphere, the south pole of the magnet points towards the south direction of the Earth. Similarly, when the same magnet is suspended in the Southern Hemisphere, the south pole still points to the south direction. This phenomenon of magnetism is used for the construction of a magnetic compass.