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What
is a magnet?
A magnet is an object that is made of materials
that create a magnetic field. Magnets have poles,Every
magnet has at least one north pole and one south
pole.
magnetic poles The points,
or poles, where their magnetic strength is concentrated.
We label them north and south because suspended
magnets orient along north-south planes. On
different magnets, like poles repel each other,
opposite poles attract.
magnetic field A magnetic
field is the region in space where a magnetic
force can be detected. The magnetic field strength
and direction can be measured in terms of strength
and direction.
Anisotropic (oriented) The
material has a preferred direction of magnetic
orientation.
Isotropic (non-oriented) The
material has no preferred direction of magnetic
orientation, which allows magnetization in any
direction.
Residual Induction, Br
Flux
density, measured in gauss, of a magnetic material
after being fully magnetized in a closed circuit.
Maximum Energy Product, BHmax The
maximum product of (BdHd) which can be obtained
on the demagnetization curve.
Maximum Operating Temperature
The maximum temperature of exposure that a magnet
can forego without significant long-range instability
or structural changes
Curie Temperature ,Tc
Temperature
at which a material loses its magnetic properties
Gauss Unit of measure of magnetic
induction, B, or flux density in the CGS system.
Gaussmeter
instrument that measures the instantaneous value
of magnetic induction, B. Its principle of operation
is usually based on one of the following: the
Hall effect, nuclear magnetic resonance (NMR),
or the rotating coil principle.
Magnetic induction ,B
the Flux per unit area of a section normal to
the direction of the magnetic path. Measured
in gauss.
demagnetization curve
Also known as the BH Curve,It is the second
(or fourth) quadrant of a major hysteresis loop.
Points on the normal curve are designated by
the coordinates Bd and Hd.Generally describing
the behavior of magnetic characteristics in
actual use.
Magnetic Flux
The magnetic induction(B) over an area(A), when
it is uniformly distributed and is normal to the
area.
Keeper A soft iron piece temporarily
added between the poles of a magnetic circuit
to protect it from demagnetizing influences. Also
called a shunt. Not needed for Neodymium and other
modern magnets.
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