Question

How can you demagnetise a bar magnet by employing alternating current?

Answer 1

• Step 1: Place the bar magnet inside a solenoid through which a high alternating current (A.C.) is flowing.
• Step 2: The rapidly reversing magnetic field of the A.C. disturbs and randomizes the alignment of the internal magnetic domains of the magnet.
• Step 3: While the current is still switched on, slowly withdraw the bar magnet far away from the solenoid along its axis.

As a result, the magnet gets completely demagnetized.