Questions & Answers

How to demagnetise a permanent magnet using current?

Answer
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Hint: Applying an electrical field (electromagnet) is one technique to make a magnet, thus it seems sense that alternating current may be used to remove magnetism as well. This is accomplished by passing AC electricity through a solenoid. Begin with a greater current and gradually lower it until it reaches zero.

Complete answer:
Place a permanent magnet inside a solenoid heading East-West through which an alternating current is flowing to demagnetize it. The microscopic atomic magnets in the permanent magnet become disoriented while the current is still running, and the permanent magnet becomes demagnetized.
A solenoid is a device that allows AC electricity to flow through it. A greater current is chosen, and it is gradually reduced until it reaches zero. Alternating current changes the orientation of the electromagnetic field by switching directions instantly. The magnetic dipoles strive to align themselves with the field, but because it changes, they end up randomised. Due to hysteresis, the material's core may retain a small magnetic field.
Heating the metal past the Curie point, producing a high magnetic field, applying alternating current, or striking the metal are all examples of demagnetization processes.

Note:
While demagnetization can happen by chance, it is frequently done on purpose when metal parts become magnetised or to remove magnetically encoded data. Demagnetization randomizes the orientation of magnetic dipoles.