Advertisement
BAR MAGNETS...
...are composed of a huge number of
tiny magnets lined up in such a way
that their magnetic effect is
compounded. Iron also contains micro-
magnets of this type, but they are all
jumbled up together in a way that
cancels out their individual magnetic
forces. If a magnet touches the iron, it
lines up the micro-magnets so that the
iron also turns into a magnet, at
least temporarily. As soon as you
take the magnet away, though,
disorganization quickly returns.
Curie temperature
Iron, steel, and related materials lose
their magnetic property at a certain
temperature. This temperature is known
as the Curie temperature after its
discoverer, the French physicist Pierre
Curie. Each material has its own unique
Curie temperature. For pure iron, it is 766
degrees Celsius. If you heat iron above
that point, it will no longer be attracted
by a magnet, although it will regain its
magnetism once you let it cool down
below that temperature again.
Magnets, Iron, and Poles |
MAGNETIC CUSHIONS:
Magnets can be stacked up with their
repelling poles facing one another, as long
as you make sure that they can't slip to
the side. The advantage of this kind of
magnetic cushion lies in the fact that it
lets you bring objects
"Transrapid"
magnetic levitation train
also floats on a magnetic cushion, which
enables it to reach speeds of up to 500
kilometers per hour without making very
much noise at all.
19
CHECK IT OUT
together in a
practically
friction-free
manner.
Magnets of
this kind are
used for
sensitive
technical
instruments. The
✔
Advertisement
