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Essay on Electro Magnetism
| Date: |
09-23-00 10:40pm |
| Subject: |
Science |
| Word Count: |
405 |
| Page Count: |
1.62 |
Electro Magnetism
Electromagnetism defined as "magnetism produced by an electric current". In
other words it is the electricity part of what holds ourselves and every bit of
matter in the universe together. This source of universal "glue" is found
within atoms themselves. As the name sounds, there are two different forces
within electromagnetism - the electric force and the magnetic force. Before the
early part of the last century, scientist studied electricity and magnetism as
different sciences. No one knew the connection between them. Electromagnetism
was found almost by accident, that a" flow of electric current (a movement of
electrical charge) creates a magnetic force" to use the words of Jack R.
White, author of The hidden World of Forces. I will first explain the magnetic
force in electromagnetism. Nearly 900 years ago, the Chinese discovered the
natural permanent magnet - lodestone or magnetite. After playing around with
this rock they discovered that when floating on a piece of wood it would always
point itself north. From this they then created a magnetic compass. To the
Chinese in that time, magnetic force seemed to be magic, but in the twentieth
century we use magnetic fields everyday. In such things as the refrigerator, the
washing machine, the dryer, and the vacuum cleaner all have electric motors. The
magnetic force can be created many different ways but the two main ones are:
Ferromagnetism - "caused by the orientation direction of certain kinds of
atoms. Electromagnetism - "caused by passing an electric current through a
conductor such as metal wire" Both of these magnetic fields, once created, is
exactly the same. Electromagnetic Radiation by definition is " the
transmission of energy in the form of waves having both an electric and a
magnetic component". It is impossible for a wave with just one or the other to
exist. The most common forms of electromagnetic radiation are radio waves and
light waves. The Theory of electromagnetic fields was developed by James Clerk
Maxwell of Scotland and published in 1865. His work was the first of many other
experiments and "theoretical" research that many other well known scientists
have used his works with there own experiments. Maxwell presented a set of
equations that completely describe the electromagnetic field. How it is produced
and charged by currents, and how it is distributed in space and time.
Accompanying the electric component is a magnetic component - which are both
equal. It may be shown that electromagnetic waves transport energy as well as
carry momentum. It way also be shown that "any other accelerated charge, not
necessarily a sinusoidal oscillating one, loses energy in the form of
electromagnetic waves"
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