Lenz' Law and Electric Generators

Lenz' Law describes the direction in which induced voltage causes current to run around a loop: the voltage pushes the current in the direction which will oppose the change in magnetic flux through the loop.
In other words, Lenz' Law states that induced currents try to maintain the original magnetic flux through a loop of wire (even though they don't quite make it).
Most electrical generators turn mechanical energy into a voltage via magnetic induction. Lenz' Law shows why the voltage produced by such generators alternates sign.
The maximum voltage produced by a generator of area A rotating in a magnetic field B at a rate of w radians per second is
```
               V(max)  =  N * A * B * w
```
where N is the number of turns in the rotating loop.

Note that the angular velocity w (radians/second) is related to the period P (seconds) and frequency f (1/second) of rotation as follows:

                                     2*pi
                    w  =  2*pi*f  = ------
                                      P

Also note that the maximum voltage V(max) is 1.41 times larger than the RMS voltage; people usually use the RMS voltage to describe ordinary wiring, such as 120-volt circuits in the home.