Methods of demagnetisation

• If a magnet is hammered, its atomic magnets are thrown out of line and it becomes demagnetized.
• Heating a magnet to a high temperature also demagnetize it.
• Stroking with another magnet to destroy the alignment of poles
• Place magnet with poles opposite to that which is induced by a d.c. current and insert into coil with d.c. current
• Place a magnet inside a solenoid connected to an alternating current supply.