Question

Repulsion is the surest test of polarity and magnetism. Explain

Answer 1

A magnet can attract the opposite pole of other magnet as well as the magnetic substance (iron cobalt nickel). SO, if A magnet attracts another object, we cannot say that the other object is a magnet. But if the magnet repels the object, then we can surely say that the other object is a magnet. Because “Like poles of a magnet repel each other”

Answer 2

When we bring a magnet towards a ferromagnetic material, magnetism may be induced in them. So they develop magnetism and so the two pieces will attract each other. Further, the force of attraction could be developed due to static electricity and induced electric charges. Repulsion eliminates attraction due to static electricity too.

    This way we cannot for sure decide that the piece that we have in our hand is a magnet or not.

   If the piece in hand repels the other piece near it, then we know for sure that the repulsion is not due to induced magnetism or induced electric charges. Hence, it is a sure test of same polarity and of magnetism.