dear students, now let’s study faraday’s
law of electro magnetic induction which is
1 of the most important concept, in the topic
of electro magnetic induction. this law states
that, due to, relative motion, between, a
magnetic field, and a conductor. we can also
consider that if there’s a conductor or
a closed coil, in both cases it’ll happen.
so due to relative motion between a magnetic
field and a conductor of coil, if, magnetic
lines, are cut, that means if relative motion
is such that, between magnetic field and a
conductor coil, if magnetic lines are cut,
or total magnetic flux. this or implies it
is 1 and the same thing because total magnetic
flux, changes, through, a coil. that means
whenever lines are cut the total magnetic
flux which is associated with the coil will
change. we can say, an e m f, is induced,
in the conductor, or coil. and this phenomena,
is called, electro magnetic induction. so
electro magnetic induction is basically induction
of an e m f in a conductor or a coil, when
a total magnetic flux through the coil changes
or magnetic lines are cut. and it’ll be
certainly due to a relative motion between
magnetic field and a conductor or a coil.
here we can also state about this induced
e m f that is important here that, the magnitude
of, induced e m f, is equal to, the rate,
at which, flux associated, with conductor,
or coil changes. or we can say that rate at
which flux is being cut. so here we can write,
mathematically we can also express it like
if in time d t, total flux change, or cut
by the conductor or coil is d phi. so here
we can write the magnitude of, induced e m
f, e is, mod of d phi by d t. here modulous
is taken because the flux may increase or
decrease, depending on that the value of d
phi by d t may be positive or negative. so
the value of e m f will be magnitude of rate
of change of flux. and we’ll study that,
the direction of this induced e m f, always,
opposes, the flux change. this we’re going
to discuss soon, in form of another law called
lenz law. and in that law we’ll study that
the direction of this e m f always opposes
the flux change. so if we remove the modulous
sign we can always write the value of e we
can write as minus of d phi by d t. and here
this negative sign signifies that the direction
of this e m f is always opposite to the rate
of change of flux.
