THE ELECTROMAGNETIC AGE
FARADAY'S DISCOVERY
CASE 1 - Moving a wire through the jaws of a horseshoe magnet.
· Result:
o Electrons only flow while the conductor moves through the magnetic field.
CASE 2 - Plunging a bar magnet into and out of the core of a coil.
· Result:
o Electrons only flow when the bar magnet moves in relation to the coil (magnetic field).
CASE 3 - Touching the iron core of a coil with a bar magnet and then removing the magnet.
· Result:
o Electrons only move through the coil when the iron core was being
magnetized or demagnetized.
Faraday's law of electromagnetic induction:
Whenever the magnetic field in the region of a conductor is moving or changing in magnitude, electrons are induced to flow through the conductor.
MUTUAL INDUCTION - A changing current in one coil, produces a changing current in a nearby
coil.
MAGNITUDE OF THE INDUCED ELECTRIC POTENTIAL
V= IR or
I = V/R
The Direction of the Induced Current
January 17, 2014