|Electricity · Magnetism|
Magnetic flux [change]
When a coil is introduced near a magnet (usually a bar magnet), then the magnetic lines of force passing through the coil is called magnetic flux. Magnetic flux is represented by the symbol , therefore we can say that = BAcos(a) and the resulting unit will be , where T is the unit for magnetic field and is the unit for area.
Faraday's Law [change]
His laws state that:
is the electromotive force, measured in volts;
is the change in magnetic flux, measured in webers;
is the change in time, measured in seconds.
In the case of a solenoid:
N is the number of loops in the solenoid.
Lenz's Law [change]
The negative sign in both equation above is a result of Lenz's law, named after Heinrich Lenz. His law states that the electromotive force (EMF) produces a current that opposes the motion of the changing magnetic flux.