What is Electricity?
Electricity is a form of energy. Electricity is the flow of
electrons. All matter is made up of atoms, and an atom has a center,
called a nucleus. The nucleus contains positively charged particles
called protons and uncharged particles called neutrons. The nucleus
of an atom is surrounded by negatively charged particles called
electrons. The negative charge of an electron is equal to the
positive charge of a proton, and the number of electrons in an atom
is usually equal to the number of protons. When the balancing force
between protons and electrons is upset by an outside force, an atom
may gain or lose an electron. When electrons are "lost" from an
atom, the free movement of these electrons constitutes an electric
Electricity is a basic part of nature and it is one of our most
widely used forms of energy. We get electricity, which is a
secondary energy source, from the conversion of other sources of
energy, like coal, natural gas, oil, nuclear power and other natural
sources, which are called primary sources. Many cities and towns
were built alongside waterfalls (a primary source of mechanical
energy) that turned water wheels to perform work. Before electricity
generation began slightly over 100 years ago, houses were lit with
kerosene lamps, food was cooled in iceboxes, and rooms were warmed
by wood-burning or coal-burning stoves. Beginning with Benjamin
Franklin's experiment with a kite one stormy night in Philadelphia,
the principles of electricity gradually became understood. In the
mid-1800s, everyone's life changed with the inventionof the electric
light bulb. Prior to 1879, electricity had been used in arc lights
for outdoor lighting. The lightbulb's invention used electricity to
bring indoor lighting to our homes.
HOW IS A TRANSFORMER USED?
To solve the problem of sending electricity over long distances,
George Westinghouse developed a device called a transformer. The
transformer allowed electricity to be efficiently transmitted over
long distances. This made it possible to supply electricity to homes
and businesses located far from the electric generating plant.
Despite its great importance in our daily lives, most of us rarely
stop to think what life would be like without electricity. Yet like
air and water, we tend to take electricity for granted. Everyday, we
use electricity to do many functions for us -- from lighting and
heating/cooling our homes, to being the power source for televisions
and computers. Electricity is a controllable and convenient form of
energy used in the applications of heat, light and power.
Today, the United States (U.S.) electric power industry is organized
to ensure that an adequate supply of electricity is available to
meet all demand requirements at any given instant.
HOW IS ELECTRICITY GENERATED?
An electric generator is a device for converting mechanical energy
into electrical energy. The process is based on the relationship
between magnetism and electricity. When a wire or any other
electrically conductive material moves across a magnetic field, an
electric current occurs in the wire. The large generators used by
the electric utility industry have a stationary conductor. A magnet
attached to the end of a rotating shaft is positioned inside a
stationary conducting ring that is wrapped with a long, continuous
piece of wire. When the magnet rotates, it induces a small electric
current in each section of wire as it passes. Each section of wire
constitutes a small, separate electric conductor. All the small
currents of individual sections add up to one current of
considerable size. This current is what is used for electric power.