Question

Demagnetization of magnets can be done by
A. Rough handling
B. Heating
C. Magnetizing in the opposite direction
D. All of the above

Answer 1

Hint: We know that a magnet can be formed when the magnetic dipoles in the ferromagnetic substance are aligned in the same directions. As a result of which the net magnetic field will be in the same direction. Therefore, demagnetization of magnet is the process of randomly aligning the magnetic dipoles by any means such that the net magnetic field should be zero or negligible.

Complete answer:
For demagnetizing a magnet, we will take some external measures to randomize the alignment of the magnetic dipoles in the magnetic material which will cause the magnet to be permanently destroyed. This means that the magnetic material will lose their magnetic properties.

Now, the ways used to demagnetize the magnets are given below:
A. Demagnetizing by rough handling: Rough handling is the process in which the magnet is subjected to rough treatment that is dropping from the height or hammering such that it will lose its magnetism. The rough handling will disturb the alignment of magnetic dipoles such that the magnetization would become weak.

B. Demagnetizing by heating: when we heat a magnet, the alignment of the magnetic dipole will be disturbed. This means that the magnetic dipoles will be randomly aligned and will be destroyed. As a result of which the magnet will be demagnetized.

C. Demagnetizing by keeping the magnet in the opposite direction: a magnet can also be demagnetized by keeping the magnet in the reverse direction, as a result of which the magnetic field will get neutralized. Due to this, the magnetic dipoles will get randomly aligned.Therefore, the demagnetization of magnets can be done by all the options given above.

Hence, option D is the correct option.

Note:When we demagnetize a magnet by the process of heating, the demagnetization will occur only above a specific temperature called Curie temperature. Also, there is a device known as magnetizer or demagnetizer which is used to magnetize or demagnetize. This tool applies a strong magnetic field in the reverse direction, so that the magnetic field will become neutralized.