Electricity and the PC
Abasicunderstandingofthepropertiesofelectricityisnecessarytobeabletounderstand
how a computer operates. There is a well-used analogy involving water through a pipe
that can be helpful in understanding the fundamentals of electrical properties.
Electricity flows through a circuit in much the same manner as water flows through a
pipe or hose. This concept is illustrated in Figure 2-5. When water is flowing through a
pipe, it is pushed along by a measurable rate of pressure. A good experiment is to go out
into your yard and water your garden with a hose. With the water turned on about half-
way the flowers bend a bit as the water hits them, but it does not push them over. If you
then turn the water u pfull blast, it not only pushes the flowers over, but the water
pressure—the force of the flow—may even damage them. Electricity also flows
through a circuit with a measurable pressure. This pressure is measured in units called
volts. Don’t attempt the same experiment with electricity in your garden, unless you are
searching for earthworms.(^32) PC Hardware: A Beginner’s Guide
Figure 2-5. An electrical current is like water in a hose