A magnet is a material that can generate a magnetic field, an invisible range of forces that attracts ferromagnetic metals such as iron, steel, and nickel. Magnets
can be classified as Permanent, Temporary and Electromagnetic. Unlike temporary magnets or electromagnets, permanent magnets do not lose their magnetism once magnetized. Temporary magnets become magnetized when placed within a magnetic field and lose magnetism when extracted. Electromagnets become magnetized when an electric current is passed through them. Permanent and electromagnets are widely used in industrial and mechanical applications. Using permanent magnets in electric motors
eliminates the need for winding wires and an external power source. This significantly increases the design options and potential savings in operations and maintenance of electric motors. There are four types of permanent magnets. These are Alnico, neodymium iron boron (NdFeB), samarium cobalt (SmCo) and ceramic/ ferrite magnets. NdFeB and SmCo magnets are strong and hard to demagnetize, however, they are expensive because they contain rare earth metals.Alnico is an alloy of aluminum, nickel, and cobalt and can be cast into several shapes and designs. Ceramic or Ferrite magnets are the most common permanent magnets today because of their strength, affordability, and resistance to demagnetization.