Methods of Demagnetization:
1. A magnet loss it's magnetic properly when it is heated strongly.
2. Practically a magnet can be demagnetized by hammering when it is placed in the east west direction.
3. The most effective process is the use of alternating current. In this method the magnet is placed inside a solenoid in east west direction and alternating current from a transformer is passed by the solenoid. The magnet is pulled out of the solenoid whereas current is passing whereas current is passing by the solenoid. The alternating current reverse the polarity of the magnetic property is gradually lost.