Electromagnetic induction
Whenever a coil of wire is brought to a static magnetic field or a stationary coil linked to the varying magnetic field, a change in the magnetic flux produces induced emf.
Electrical current can be generated through a change in magnetic flux in a varying magnetic field.
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| The process of electromagnetic induction |
Faraday's law of the electromagnetic induction
An English scientist Micheal Faraday gave the law of electromagnetic induction.
Faraday's law of electromagnetic induction states, "an emf or voltage is induced when the magnetic flux changes with time linked to the coil".
The rate of change of magnetic flux, emf will be induced
induced emf = - d/dt magnetic flux
Minus sign shows the Lenz's law
Lenz's law shows the direction of the induced field. The induced voltage or emf is in the opposite direction to flux.
Fleming's right rule is used for the direction of emf, the motion of the conductor, and the magnetic field.
Electromagnetic induction is used to power electrical devices such as electric motors, generators and transformers, and more.
The source of electromagnetism is the electric current flowing through a coil of wire.
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| Emf induces when there is relative motion between coil and permanent magnet |
Uses
It is used in electrical devices such as electrical generators(hydroelectric dams), electric motors, transformers, etc
Where mechanical power is used to move the magnetic field to generate a voltage
Induction motors, current lamp
Loudspeaker, headphones
Magnetic data storing devices VCR, recording tape, hard disk, and more
Electric bells, transformers, and
The advantages of electromagnetic induction are:
Electrical power(AC or DC) can be generated by using electromagnetic power sources.
There is no need for external electrical sources to produce electrical power.
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