In this topic, you study Magnet – Definition, Types & Applications.
Any substance which possesses the power Of attracting pieces Of iron is known as a magnet.
TYPES OF MAGNETS
Depending upon their ability to retain magnetism, the magnets can be classified into two categories : Permanent magnets and Temporary or Electromagnets.
(i) Permanent Magnets : The permanent magnet is made of a material (e.g. steel alloys containing tungsten, chromium, cobalt or iron alloys containing high percentage of nickel, aluminium, cobalt) that remains magnetized for long periods of time without the need for an external source of energy.
Applications: Such magnets are commonly used in electrical measuring instruments(e.g. permanent magnet moving coil instruments, energy meters, etc.), small electrical generators and motors, speedo-meters, telephones, loud speakers, microphones and a great variety of other gadgets.
(ii) Electromagnets: An electromagnet which consists of a soft iron core wound with a coil, acts as a magnet as long as the current flows through its coil.
Applications: Such magnets are commonly used in electrical machines such as motors, generators and transformers. They are also used in electrical measuring instruments, relays, circuit breakers and numerous other electrical devices.