Descriptions and explanations of some applications of the concept of magnetic field are presented below. Applications such as electromagnets, AC and DC electric Motors, electric generators, electric transformers, electromagnetic wave propagation, maglev (Magnetic Levitation) and magnetic Resonance Imaging system are all discussed.
Electromagnets are magnets where the magnetic field is produced by an electric current. They are made up of a large number of turns of wire in order to create strong magnetic fields. Electromagnets can be switched on and off and are therefore flexible means of displacing heavy metallic objects from one point to another. Electromagnets have many uses in industry.
A) DC motor principle
B) AC motor principle
An electric generator is a device that converts mechanical energy into electrical energy using the principle of electromagnetic induction discovered by Michael Faraday: a difference of voltage is created between the end of a electric conductor moving in a magnetic field. This difference of voltage can be used to move electric charges thus generating an electric current.
Electric TransformersSee How do Electric Transformers Work? in this website.
Electromagnetic wave propagation
Electromagnetic waves are a combination of changing electric and magnetic fields that transport electromagnetic energy from one point to another. The electric and magnetic fields associated with electromagnetic waves are vectors in planes perpendicular to each other. The direction in which the electromagnetic energy propagates (transport electromagnetic) is perpendicular to the two planes containing the electric and magnetic fields.
Some of the well known systems that use electromagnetic waves are: antennas, waveguides, radio and TV broadcasts, radar, satellite, optical fibers etc...
Maglev (Magnetic Levitation)
Maglev are the fastest trains systems in the world and they use the basic principles of attraction and repuslion in magnetism. A maglev train is suspended (levitated) above a track without touching it to reduce frictions using magnetic repulsion, and propelled by a linear induction motor. Hence magnetic field is used for both levitation of the train and its propulsion.
Magnetic Resonance Imaging
An MRI (Magnetic Resonance Imaging) system in medicine uses a combination of a magnetic field and radio (electromagnetic) waves to generate images of parts of the human body, such as the brain, spine, joints, abdomen, breast, heart and many other parts of the body. The images generated are then analyzed in order to find out if a given body part is functioning normally or not.