(N/A) When iron filings are sprinkled on a glass plate placed over a bar magnet,they align themselves along the magnetic field lines of the magnet.
The resulting pattern suggests the following:
$(i)$ The pattern of the iron filings indicates that the magnet has two poles,similar to the positive and negative charges of an electric dipole. One pole is designated as the north pole and the other as the south pole.
$(ii)$ When the magnet is suspended freely,these poles point towards the geographic north and south poles,respectively.
$(iii)$ $A$ similar pattern of iron filings is observed around a current-carrying solenoid,which confirms that a bar magnet and a current-carrying solenoid behave similarly.