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Transcript
By NEHA TIWARI
XII_PHYSICS
ELECTROMAGNETIC INDUCTION
Faraday's Discovery
FARADAY'S EXP.
He discovered that relative motion between a bar magnet and a wire loop produced a small current in the latter.
Also
The relative motion between the coils induces the electric current.
ANOTHER
FINDING
Faraday showed that this relative motion is not an absolute requirement.
MAGNETIC FLUX
Magnetic flux through a plane of area A placed in a uniform magnetic field B is given by
MAGNETIC FLUX
FORMULA
FARADAY'S LAW
OF INDUCTION
FARADAY'S LAW
The magnitude of the induced emf in a circuit is equal
to the time rate of change of magnetic flux through the
circuit.
LENZ'S LAW
LENZ LAW
The polarity of induced emf is such that it tends to produce a current
which opposes the change in magnetic flux that produced it.
CONSERVATION OF ENERGY
MOTIONAL EMF
E =B l v
MOTIONAL EMF & EDDY CURRENT
EDDY CURRENT
EDDY CURRENT
APPLICATION
APPLICATIONS OF EDDY CURRENT
3
2
1
Magnetic braking in trains
Electromagnetic damping
Induction furnace
&
ELECTRIC POWER METERS
INDUCTANCE
INDUCTANCE
CONSTANT OF PROPORTIONALITY =INDUCTANCE
(SCALAR QUANTITY) & SI UNIT =HENRY
9H
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