Electromagnetic induction is one of
the interesting concepts in physics. Every electric field creates a magnetic
field and every magnetic can able to create an electric field. Michael Faraday is
credited with the discovery of electromagnetic induction in 1831.
 |
| Electromagnetic Induction Motor |
An anecdote about the life incident
of Michael Faraday
Once upon a time, Michael Faraday demonstrated his
experiments which led to the discovery of electromagnetic induction. At the end
of the lecture, one member of the audience approached Faraday and said, “Mr.
Faraday, the behaviour of the magnet and the coil of wire was interesting, but
what is the use of it?” Faraday answered politely, “Sir, what is the use of a
newborn baby? Yes, Yes, Yes definitely that newborn baby now a multiple
capacity of Young man. If we want to understand electromagnetic induction, we have
to go through it from the beginning of the newborn baby.
Magnetic flux (фB)
The magnetic flux through area A in a magnetic field is
defined as the number of magnetic field lines passing through that area
normally.
Faraday's law of induction
First law
Whenever magnetic
flux linked with a closed circuit changes, an EMF is induced in the circuit.
Second law
The magnitude
of induced EMF in a closed circuit is equal to the time rate of change of
magnetic flux linked with the circuit.
Lenz’s law
Lenz’s law states that the direction of the induced current
is such that it always opposes the cause responsible for its production.
Self-induction
An electric current flowing through a coil will set up a
magnetic field around it. The magnetic flux of the magnetic field is linked
with that coil itself. If this flux is changed by changing the current, an emf
is induced in that same coil. This phenomenon is known as self-induction.
Mutual induction
When an electric current passing through a coil changes with
time, an EMF is induced in the neighbouring coil. This phenomenon is known as
mutual induction and the emf is called mutually induced emf.
Tags
physics