Question

While magnetizing an iron piece, why do we move only one pole of the magnet over the iron piece?

Answer 1

We move only one pole of the magnet over the iron piece

1. Magnetization is achieved by rubbing a piece of iron with both ends, like the north pole of a magnet.
2. This should be repeated several times without changing the poles or direction of friction. When a magnet rubs against a metal object, the electrons align and magnetize the object.
3. In this process, if we change the pole of the magnet alignment of an electron could be changed, and magnetization gets disturbed.

Hence We move only one pole of the magnet over the iron piece.