Application Of Magnets For Levitation
Uploaded by jasonwoody on Aug 21, 1999
In ancient times men knew of a special kind of rock that could pull other rocks of the same kind and pieces of iron toward themselves. Such rocks were called lodestones. Today man uses the same force exerted by electromagnets and permanent magnets to provide magnetic aide to trains and more efficient power generators. This report will focus on the use of magnets in the generation of electricity and magnetically aided trains.
Magnetism is defined as the force exerted by a magnetic field. A magnetic field is defined as the energy exerted by the magnet. It is caused by the alignment of the domains (sub-atomic particles) of an object. When the domains are lined up they produce magnetism. When the domains are not lined up then they cause the object to be demagnetized (having no magnetic power). Materials such as air, wood, copper, and water do not respond to the power of magnets. We then ask "Why and how is it possible to make a magnet out of copper." Good question, and simple answer. Copper becomes magnetic when an electric current is run through it while spiraled around a magnet. Thus it is called an electromagnet.
The following facts are to state the properties of magnetic force:
1. If free to rotate, permanent magnets point approximately north-south.
2. Similar poles repel, dissimilar poles attract.
3. Permanent magnets only attract objects with domains.
4. Magnetic forces act at a distance, moreover through nonmagnetic barriers. 5. Things attracted to permanent magnets (other than permanent magnets) also become temporary magnets.
6. A coil of wire with an electric current flowing through it becomes an electromagnet.
7. Putting iron inside the coil greatly increases the strength of an electromagnet.
8.Changing magnetic fields induce electric currents in copper and other conductors.
Some people like to talk about animal magnetism as a metaphor. Most people do not know that it actually exists. There are very weak magnetic fields around Homo-sapiens. The field can be detected by the Superconducting QUantum Interference Device (SQUID).
Magnets play a key role in the generation of electricity. Figure two below illustrates magnets in a generator. In order to produce electricity either the loop or the magnets must be rotated relative to one another.
The energy for this rotation can be provided by a variety of sources. One source is water which can be converted to steam, and is then used to drive turbines that operate generators. The energy to boil the...