Name: Allison Williams
Date: Around 1993
How does an electrical current work?
This is a nice exercise in getting kids used to using a terminal,
but NEWTON is not your school library's encyclopedia. Current happens when
electrons all move in one direction inside a wire.
Actually, there are many volumes of books on the subject.
Electrical current(s) are not only transmitted by wire, but also other
mediums, such as air in a device called a wave guide when dealing with UHF
(Ultra High Frequency electricity) or Microwave (even higher frequency). The
mechanics of electron (or hole) flow is and will continue to be a subject of
considerable debate. The effect of that current is what we all know about.
As I said, there are volumes and volumes of books on the subject. In short,
electrical current can flow only when there is a potential (commonly referred
to as voltage) between two sources, and a path to equalize the potential.
This potential can be created by many sources, including chemical energy, heat
energy, and just about any force that can create substances that are charged
more or less positively or negatively. A battery, for example, is made of two
or more chemicals or elements that are reacting to cause an electrical
potential between two elements. By connecting the two elements with a
conductor of some type, or a "load," electrical current will flow in an
attempt to equalize the differing electrical charges. When the chemical
reaction is complete, and the charges have been neutralized, no more
electrical current can flow. Sometimes the simplest questions can be the most
difficult to answer. Keep asking them.
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Update: June 2012