physics a2, generators

1. Generators

2. • The structure of a simple generator is
essentially the same as a motor. The
difference is that now mechanical energy is
converted into electrical energy.
Consider a coil of area A with N turns of wire rotating at a constant angular velocity w in
a uniform magnetic flux density B. As the coil rotates, it cuts through the lines of flux.
Another way to express this is to say that the flux linking the coil is changing.
At what point is the rate of flux-cutting greatest?
Rate of flux cutting = induced emf = BANwcos wt
with a maximum value, Eo = BANw when the coil is perpedicular to the field.
To increase the voltage induced you can increase B, A, N, w
W = 2 pi f

3. Powerstation generator
Inside the generator they move the magnet
and have 3 coils equidistant inside the
generator.
This leads the generator having 3 induced
currents for 1 magnet.
See book – p 128

4. Flemming’s RIGHT hand Rule
Notice – induced current! Only use this in generators!