© 2001 John Wiley & Sons
Electric Power Generation
So far in this chapter, we have looked at what electricity is and how it’s distributed. In
this section, we’ll discuss how it’s generated. We’ll see how fossil fuels such as coal, oil,
and natural gas are used to produce mechanical motion and how that mechanical motion
is used to produce electric power. We’ll also examine solar and wind power generation.
Questions to Think About: How can a moving object push electric charges through a
wire and produce electricity? Why are generating plants often built near bodies of water?
What is the purpose of the giant cooling towers near some power plants? How does a
power plant determine how much power it needs to generate, and what happens to its
generators when the demand for power suddenly increases or decreases?
Experiments to Do: There are a few household generators. One of these is a bicycle gen-
erator, a small device that uses the rotation of a bicycle’s wheels to produce electricity for
its lamp. Find a bicycle generator and turn its rotor (its central spindle) with your fin-
gers. You will find that the rotor spins relatively easily when the generator is discon-
nected from the lamp but becomes much harder to turn when the generator is powering
the lamp. The rotor contains a magnet, which moves near several coils of wire as the rotor
spins. These coils can only carry current when they’re connected in a circuit. How does
that need for a circuit explain why the rotor is harder to turn when the generator is con-
nected to the lamp? What is the relationship between the work you do on the generator
and the power consumed by the lamp?
CHAPTER 9. ELECTRODYNAMICS
Generating Electric Currents
In Section 9.2, we saw that a change in the magnetic flux passing through a trans-
former’s secondary coil causes current to flow in that