Suppose you have two bars, one of which is a permanent magnet and the

other is not a magnet but is made from a ferromagnetic material like iron.

the two bars look exactly alike. explain how you can distinguish the look-

alike bars with the aid of a third bar that is not a magnet, but is made from a

ferromagnetic material.

The third bar, which we can call the test bar, is known to be a magnet, so it has a north pole and a south pole. Bring one end of each of the two unknowns near the magnet. That unknown bar which is a permanent magnet will be attracted to the test bar when opposite poles are brought together, but it will be repelled from the test bar when like poles are brought together. Both ends of the unknown bar which is a ferromagnetic bar, will be attracted to the test bar. The magnetic field of the test bar will always induce a pole that is opposite in polarity to the pole of the magnet. Ferromagnetism always results in attraction. Hope this helps a lot :)