When people think of electricity they think of radios, TV,
computers, light bulbs, microwaves, refrigerators, water heaters
and much, much more. All those things are part of our every day
life. Just think, that if there were no electricity you wouldn't be
reading this article right now, because your computer would not
work. Or if you just got
a new TV, you plugged it in the outlet
and it wouldn't work because a TV doesn't work on its own, it
needs the help of electricity.
Generating electricity
Have you ever wondered how a power plant makes
electricity? It's pretty simple. A mechanical energy used for
powering magnetic generators is transformed into electrical
energy. Magnetic generator is basically a coil of wire that rotates
between two magnets. Due to magnetic field between these two
magnets electrons
in the coil are propelled along the wire. As the
coil keeps rotating, during one half of a turn, the electricity
travels one direction through the coil. During other half, it
travels other direction. One complete revolution of the coil is
called a cycle. The number of such cycles in a second is called
the frequency of the voltage or current. In this case alternating
current.
Electric charges
Have you ever heard of protons, electrons and neutrons?
They are tiny particles forming atoms. Atoms are only one-
hundred-millionth of inch in diameter. Electrons have a
negative charge. Protons and neutrons are made from smaller
particles called quarks. Protons are made up of two quarks with
2/3 positive and one quark with 1/3 negative . So, protons are
positive. They have the same sized charge as an electron only it
is positive. Neutrons contain two quarks with 1/3 negative and
one quark with 2/3 positive, so they are neutral.
In an atom protons and neutrons form nucleus, the center of
an atom. The nucleus has a positive charge. The negative
electrons orbit around it. The atom is therefore electrically
neutral.
Ions
Sometimes an atom loses or gains an electron, when this
happens it's called an ion. If it loses an electron then it gains a
positive charge. If it gains an electron it gains a negative charge.
In some materials an electric charge flows better then
others. Those materials are called conductor. Most of the
conductors are different kinds of metals [copper, gold, silver,
bronze, and steal]. Metal is a good conductor because they have a
lot of free electrons in them. An insulator is the opposite of a
conductor. It is hard for an electric charge to go through them.
That's because the electrons inside them are tightly joined
together in atoms, in simpler words the electrons are not free to
move around.
Electric current
There are two kinds of currents, direct current and
alternating current. In our homes we have alternating current,
but in batteries there is the direct current. When there is
alternating current it flows back and forth very fast in an cable.
Direct current goes only one direction in a cable or more likely
in this case in a wire.