Faraday Laws of Electromagnetic Induction
Faraday’s law of electromagnetic induction is a basic law of electromagnetism relating to the operating principles of transformers, inductors and electrical motors and generator. The phenomenon by which an emf is induced in a conductor when it is cut by magnetic flux is known as electromagnetic induction.
Faraday First Law:
It states that,”When a conductor cuts a magnetic field an Electro Motive Force (EMF) is induced in it due to change of flux”. The induced EMF is in direction so as to oppose the cause producing it.
Faraday Second Law:
It states that the EMF induced is directly proportional to the rate of change of flux., with the increased rate of change of flux, the magnitude of induced EMF will be increased and vice versa. The mathematical form of Induced EMF is:
The minus sign represents that the induced EMF or current sets up in a direction so as to oppose the cause of it.
Induced EMF could be classified as dynamically induced emf and statically induced EMF.
Statically induced EMF:
The EMF produced in a conductor due to the change in magnetic field is called statically induced EMF. It can be further divided into two types:
(i)Self Induced EMF (ii) Mutual Induced EMF
Dynamically Induced EMF:
The EMF induced due to motion of a conductor in a magnetic field is called dynamically induced EMF.
Fleming’s Right Hand Rule:
Fleming’s right hand rule is used to find the direction of induced EMF in a conductor.
“According to Fleming’s right hand rule the directions of the magnetic field, the induced current, and the motion of the conductor are indicated respectively by the first finger, second finger, and thumb of the right hand when these are held out perpendicular to each other”.
“According to Lenz’s law the direction of an induced current is always such as to oppose the change in the flux or the magnetic field that produces it.”