Magnets attract when two opposing poles are brought together and repel when they have similar poles. Magnets come with a north pole and south pole. If one end of a magnet is the north pole and the end of the other magnet is the south pole, both pieces will attract; magnets will repel if two north poles or south poles are brought together.
Magnets refer to any object that exhibits a magnetic field. There are three major groups of magnets: permanent magnets, temporary magnets and electromagnet.
- Permanent magnets - permanent magnets refer to objects that retain their magnetism once magnetized. Common examples include the magnets used on refrigerator doors. Permanent magnets are typically made of ferromagnetic materials, such as cobalt, nickel, iron and some rare earth metals
- Temporary magnets - temporary magnets become magnetized when they come within range of a magnet, but the magnetism only lasts for a short while. Soft iron item, such as needles and paper clips, are good examples
- Electromagnets - electromagnets are magnets made by wire loops around a core material. When electricity is passed through the wire, it induces a magnetic field. The strength of the magnet becomes even stronger if the core material is ferromagnetic. Electromagnets are common in electronic devices such as radios,televisions and computers. They are also used in industrial sites for heavy duty lifting with cranes