The Greeks were the first to use the magnet. A magnet has the property of attraction. Magnetism is the force of attraction that occurs when atomic electrons are arranged in an orderly manner in any material. For example iron. Types of Magnets.
1. Natural magnets
2. Artificial magnets
What are Natural Magnets
Stones and minerals that are naturally attractive are called natural magnets. For example, magnetite, and earth.
What are Artificial Magnets
Magnets formed by rubbing iron or steel bars with natural magnets in a proper manner are called artificial magnets. There are two types of artificial magnets. 1. Permanent magnets, 2. Temporary magnets
Permanent Magnets: In these the magnetism is permanent. For example, a bar magnet, horseshoe magnet, cylindrical magnet, spiral magnet
Temporary Magnets: In these, the magnetism lasts only for as long as current flows in the coil. For example electromagnets
Magnetic properties
1. Theory of Magnetic Poles
⦁ The coefficient of attraction is maximum at magnetic ends. So those points are called poles. These are known as the South Pole and the North Pole.
⦁ Homogeneous magnetic poles repel and unlike poles attract. It is used in determining the poles of artificial magnets.
⦁ The correct test for repulsive magnetism. The distance between the poles of a magnet is called the length of the magnet. It is about 5/6th of the physical length of a magnet.
2. Law of pair of magnetic poles
Magnetic poles are always paired. These cannot be separated. That is, there is no single magnetic pole.
3. Attraction virtue
When a magnetic material is brought close to a magnetic pole it is attracted by that magnetic pole.
4. Directionality
If a bar magnet is hung horizontally in the air it will always point north and south of the earth. This is called the magnetic directional principle. A compass works based on directionality.
5. Motivation virtue
When one magnetic pole is brought close to a magnetic material such as iron, an opposite pole is induced in it.