Page 143 - Science Class 06
P. 143
NATURAL AND ARTIFICIAL MAGNETS mes. Now, the needle is ready to use like a
You have already studied that there are magnet. You can test its magne c power by
natural rocks which show magne c taking it close to some iron fillings.
property (natural occurring magnet). The Double Touch Method
However, we can also make ar ficial In this method, two bar magnets are used.
magnets. Depending upon requirement, Their opposite poles, i.e., north pole of a
permanent and temporary magnets are magnet and south pole of the other are
made. brought together in the middle of the bar
Permanent Magnet : To make permanent which has to be magne sed. Now, move
magnet, we require such materials which from the middle, in opposite direc ons to
can retain the magne c property for longer each other. Both magnets are then li ed
period of me and can be easily magne sed. together and again brought in the middle of
Temporary Magnet : To make temporary the bar. We repeat this for 30-40 mes. In
magnets, we need such materials which can this, way we can make stronger magnets.
easily lose or a ain the magne c property TAKING CARE OF MAGNETS
faster. They retain the magne c property as We should take proper care of magnets,
long as the magne sing force is available. otherwise they may lose their magne c
When electric current is allowed to pass property. A magnet may lose its magne c
through a coil, wound around a rod, the rod property if:
acquires magne c field, it acquires mag-
v we knock it on the hard surface;
ne sm. Steel is used to make permanent
magnets whereas alloys like alnico (alumi- v we beat or hammer it;
nium + nickel + cobalt) and so iron are used v we heat it.
to make temporary magnets. We should know the important methods to
MAKING AN ARTIFICIAL MAGNET keep magnet in proper condi on.
There are two methods to make ar ficial We should keep magnet on a magne c
magnets: keeper. We can also keep two bar magnets
The Single-Touch Method in the posi on as magnet are kept in
magne c keeper. To keep one horse shoe
In this method, we put an iron piece such as
shaped magnet, we can use only one iron
a needle on the table and then stroke it
bar.
with one pole of a bar magnet in one
direc on only. When we reach near the end
of the needle, we li the magnet and bring
its same pole back to the star ng point of
the needle. We repeat this about 30-40 (7) (3)
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