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04/24/10(Sat)22:43:16 No.220475XXX  >>220472839
Magnetic Fields
A
magnet is an object that attracts certain metals by use of it's
magnetic field. These metals include iron, cobalt and nickel. The space
around the magnet contains the magnetic field, which is created by the
movement of negatively charged electrons. Electrons have mass, and a
slight charge. In magnetic metals, the electrons are unpaired, and spin
in the same direction, creating magnetic domains, or lines of force,
that travel in the same direction.
Magnetic Lines of Force
The
magnetic field of a magnet is the boundaries of it's magnetic lines of
force. These are the north to south lines in a magnetic field. Magnetic
lines of force always start at the north end of a magnet and end on the
south end, just like the Earth's axis. Any magnet will set itself
parallel to the lines of force, which is how compasses work, and why
magnets repel or attract magnetic materials, depending on the
north-south position of the magnetic lines of force.
Magnetic
lines of force draw near each other when the come close to the north and
south poles, or ends, of the magnetic, but grow farther from each other
as they move away from the poles. They do not cross over each other.
Types
of Magnets
There are three types of magnets. Hard, or permanent,
magnets are just like their name, permanently magnetic. They make their
own magnetic fields constantly. Soft, or temporary, magnets only create
magnetic fields when they are under the influence of a hard magnet's
field. They will continue producing a magnetic field for a short while
after leaving the field of a permanent magnet.
Electromagnets
are artificial magnets that create a magnetic field only when
electricity travels through them. They are made with wire coils. When
the electricity moves through them, electrons are created and their
movement makes a magnetic field. The size of the field can be controlled
by the amount of wire coils and the amount of electricity that is sent
through them. |
