How can you demagnetise a magnet? Explain.

Ways to demagnetise a magnet :

1. By Rough Handling or Improper Storage : Rough handling, frequent dropping, or storing magnets without soft iron keepers causes gradual weakening of magnetism over time which results in self-demagnetisation.
2. By Dropping the Magnet on a Hard Surface : When a magnet is dropped repeatedly on the floor or a hard surface, it experiences sudden mechanical shocks which disturb the alignment of the magnetic domains inside the magnet. As a result, the magnet gradually loses its magnetic strength and becomes demagnetised.
3. By Hammering the Magnet Repeatedly : When a magnet is hammered repeatedly, disorientation of the molecules of the magnet occurs. This results in loss of magnetism altogether.
4. By Heating the Magnet : If a magnet is heated to a very high temperature and then allowed to cool in the east-west direction, it loses magnetism. On heating the magnet, its molecules gain thermal energy and then kinetic energy increases. This breaks the chain of molecules and results in demagnetisation of the magnet.
5. By Passing Alternating Electric Current : If a magnet is placed inside a coil of insulated copper wire and alternating current is passed through the coil, the direction of the magnetic field keeps changing rapidly which disturbs the orderly alignment of the molecules of the magnet, resulting in demagnetisation of the magnet.