Electromagnetism describes the relationship among electricity and magnetism. Almost everyone, at some time or another, has had the chance to play with magnets. Most of us are aware with bar magnets or those thin magnets that typically end up on refrigerators. These magnets are termed as permanent magnets. Even though permanent magnets attain a lot of exposure, we utilize and based on electromagnets much more in our everyday lives. Electromagnetism is necessary the foundation for all electrical engineering. We utilizes electromagnets to produce electricity, diagnose illnesses, produce pictures, on a television screen, store memory on our computers and in just about every other aspect of our lives that based on electricity. Electromagnetism is the key to the operation of a great number of electrical devices utilized in home as well as industry. Transformers, , generators, motors circuit breakers and relays are some instance of widely utilized electromagnetic devices.
Electromagnetism works on the principle that an electric current through a wire generates a magnetic field. Whenever electric current pass through a conductor, a magnetic field is generated in the space surrounding the conductor. This magnetic field is the same kind of force that makes metal objects stick to permanent magnets. In bar magnet, the magnetic field runs from the north to the South Pole. In a particular wire, the magnetic field forms around the wire. If we wrap up that wire around a metal object, we may frequently magnetize that object. In this way, we may create an electromagnet.
In this unit, we shall discuss about electromagnetism and learn the relationship that exists among electric current and magnetic flux. Magnetic circuit provides path for magnetic flux and it is the basis of electromagnetism. We will learn about several types of magnetic circuits which can be series or parallel.
The way in which electric current magnetizes a magnetic material shall be discussed in magnetization curve or B-H curve. The magnetization curve caused by raising current is not the same while the current decreases and this phenomenon is called as magnetic hysteresis and this shall also be discussed.