25.3. Generating and Using Electricity http://www.ck12.org
FIGURE 25.11
This diagram shows the basic parts of an
electric generator. Compare the genera-
tor with the electric motor.Generators may be set up to produce either alternating or direct current. Generators in cars and most power plants
produce alternating current.
- A car generator produces electricity with some of the kinetic energy of the turning crankshaft. The electricity
is used to run the car’s lights, power windows, radio, and other electric devices. Some of the electricity is
stored in the car’s battery to provide electrical energy when the car isn’t running. - A power plant generator produces electricity with the kinetic energy of a turning turbine. The energy to turn
the turbine may come from burning fuel, falling water, or some other energy source. You can see how falling
water is used to generate electricity inFigure25.12 and in the video at this URL: http://www.youtube.com/w
atch?v=cEL7yc8R42k.
FIGURE 25.12
A hydroelectric power plant uses the ki-
netic energy of falling water to turn a
turbine and generate electricity.Electric Transformers
Anelectric transformeris a device that uses electromagnetic induction to change the voltage of electric current.
A transformer may either increase or decrease voltage, but it only works with alternating current. You can see the