Question

GIVE REASONS -
1. The poles of an electromagnet can be reversed.
2. Iron fillings arrange themselves in closed loops around a bar magnet.

Answer 1

Dear student,
1.Unlike other magnets, the poles of an electromagnet can be reversed by reversing the connection of the wire at the source of electricity.Thus, reversing the flow of electricity through it.This feature of reversing the polarity is important in making or producing electric motors.
2. Iron fillings arrange themselves in closed loops around a bar magnet.This is because the magnet creates its influence in the region surrounded by it and iron filings experience a force.This force makes the iron filings to arrange in a particular order or pattern.Each piece of iron filing acts as a small magnet and experience a force in certain distance in magnetic field.Thus, forming a closed loops which act as magnetic field lines.
Regards