GEOLOGY

Detailed explanation-1: -A permanent magnet can be demagnetized or can loose its magnetism if it is heated at appropriate temperature. Due to heating, the orientation of domains of the magnet changes and its magnetic properties are reduced or lost completely.

Detailed explanation-2: -When a permanent magnet is exposed to increased temperatures for a length of time, the electrons will be forced out of alignment and the magnet will be demagnetized, either partially or completely. The resulting demagnetization may be reversible, or it may be irreversible.

Detailed explanation-3: -In the case of rocks and minerals, remanent magnetism appears below the Curie point-about 570 °C (1, 060 °F) for the common magnetic mineral magnetite. This temperature is named for the French physicist Pierre Curie, who in 1895 discovered the laws that relate some magnetic properties to change in temperature.

Detailed explanation-4: -Heating magnet to very high temperature. Dropping the magnet frequently. Hammering the magnet repeatedly. Bringing the magnet in contact with the like poles of other magnets repeatedly. Passing the electric current through magnet. More items