Generators produce electricity through alternating current. They work by having either a coil rotate inside a magnet or a magnet rotate inside a coil. As the magnet passes through the coil, it induces a current that changes direction with each half rotation, producing an alternating current. Large generators commonly produce alternating current because it is easier to convert to direct current if needed than the reverse.

1. GENERATORS

2. Induced Current in a Generator
The effect of inducing a current in a coil by moving a
magnet inside it is used for the generation of
electricity in power plants
There are TWO TYPES OF GENERATOR.
Both turn rotational energy into electrical energy.
1. One type involves rotating a coil inside a magnet.
2. The other type involves rotating a magnet inside
a coil
Both types produce ALTERNATING CURRENT.

3. An electric generator consists of a:
• MAGNET- creates a magnetic field, and a
• LOOP OF WIRE- rotates in the magnetic field
As the wire rotates in the magnetic field, the changing
strength of the magnetic field through the wire
produces a force which drives the electric charges
around the wire.
As the loop spins, the direction of the force changes,
so too then does the direction of the current .
The changing direction of the force after every 180
degrees of rotation gives the alternating current.

5. Slip
ring

6. ALTERNATING CURRENT
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7. ALTERNATING CURRENT
• The rate of oscillation for the sine wave is 60 cycles
per second. Oscillating power like this is generally
referred to as AC, or alternating current.

8. ALTERNATING CURRENT
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• Large electrical generators happen to
generate AC , so conversion to DC would
involve an extra step.
• It is easy to convert AC to DC but
expensive to convert DC to AC, so if you
were going to pick one or the other AC
would be the better choice.