Page 81 - Science Class 6 Times Publication

Test for magnetism

A magnet attracts magnetic substances. It also attracts another
magnet. We can distinguish a magnet from a magnetic substance
with the help of following tests:

1. Testing the repulsion between the two poles

Perform the following experiment to test whether the given substance
is a magnet or a magnetic substance.
a. Suspend the given substance
in a stand with the help of a
thread.

b. Bring N pole of a bar magnet
near one of the poles of the
suspended substance. Then
observe whether there is
attraction or repulsion.
c. Again bring S pole of the bar magnet near the same pole of the
suspended substance. Observe whether there is attraction or
repulsion.

If there is attraction with both the ends of the magnet, the suspended
substance must not be a magnet. It must be a magnetic substance.
But, if there is repulsion with one pole of the magnet and attraction
with the other, the suspended substance must be a magnet. It is
because there is repulsion only when the suspended substance has
north and south poles, i.e. it is a magnet. Hence, repulsion is the sure
test for magnetism.

2. Testing the directional property of the given substance
A freely suspended magnet always comes to rest pointing north
and south directions. But a magnetic substance may point at any
directions while coming to rest. To test whether the given substance
is magnet or not, suspend the given substance in a stand and allow
it to move freely. It will come to rest after some time. Observe the
directions to which it is pointing and make it move. If the substance
points the same directions (i.e. north and south) in all cases, then
the given substance must be a magnet. Otherwise, it is a magnetic
substance.

Times' Crucial Science and Environment 77 Book 6