Faraday's Law
http://subato.blogspot.com/2011/02/faradays-law-of-induction-and.html
Faraday's law states "An emf E is induced around a
closed loop if the magnetic flux through the loop
changes. The magnitude of the emf is
and the direction of the emf is such as to drive an
induced current in the direction given by Lenz’s law."
(knight). In order to understand Faraday law we must
understand the concept of magnetic flux. Magnetic flux
is a way of measuring the total amount of magnetic
field over a surface or a surface area it analogous to
the flow of water and basically out lines the flow of
the magnetic field passing through a surface.
The above photo illustrated the applications of
Faraday's Law and different ways to manipulate the
amount of magnetic flux going through the wire. The
top right illustration shows that by increasing the
number of wire coils around the cylinder. As you can
see by increasing the number of coils we increase the
amount of wire that the flux can pass through
effectively increasing the flux through the wire and
increasing the current.
In the second illustration the loop of wire is moved
in and out of the magnetic field increasing and
decreasing the amount of flux passing through the
center of the loop increasing and decreasing the
current trough the wire.
In the third illustration the wire is held stationary
and a magnet is moved through the center of the coil
increasing the amount of flux passing through the wire
when the magnet is brought further into the center of
the cylinder and deceasing the flux when it is brought
out effectively changing the magnetic field.
In the final illustration the wire is rotated in a
constant magnetic field this changes the amount of
surface area available for the magnetic flux to pass
through effectively increasing and decreasing it which
causes current to flow through the wire. Paying
attention to the formula this it where the changi in
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