Magnet Classification

Magnets can attract iron, nickel, cobalt and other metals, commonly known as magnets. It can be divided into common permanent magnets and electromagnets that are magnetic only when energized. If the magnet is made into a rod or needle and suspended, it will naturally point to the earth's south pole and north pole. Magnets are divided into large magnets and small magnets.
Large magnets Magnets are widely used, and electromagnets are used to make cranes for transporting steel. When electrified, it becomes a powerful magnet, so it can attract heavy steel. Just cut off the power when putting down the steel.
Small magnets Compared with large magnets, the compass appears small, light, and much weaker. The function of the compass is not to attract iron, but to reflect the magnetic force of the earth.
The property of magnets to attract iron, cobalt, nickel and other substances is called magnetism. The magnetically strong areas at both ends of the magnet are called magnetic poles, one end is the north pole (N pole), and the other end is the south pole (S pole). Experiments have proved that the same-sex magnetic poles repel each other, and the opposite-sex magnetic poles attract each other.
There are many original magnets with two opposite magnetic poles in iron. When there is no external magnetic field, these original magnets are arranged in disorder, and their magnetism cancels each other, and they do not show magnetism to the outside. When the iron is brought close to the magnet, these original magnets are neatly arranged under the action of the magnet, so that the end close to the magnet has the opposite polarity to the magnet and attracts each other. This shows that the iron can be magnetized by the magnet due to the existence of the original magnet. Metals such as copper and aluminum do not have the original magnet structure, so they cannot be attracted by the magnet.