Question

A permanent magnet becomes weak with time.why.

Answer 1

Permanent magnet loses its magnetism because of 4 reasons 1-when it is heated above a point called curie temperature 2-via shock 3-near a demagnetising field 4-when they are subjected to heat It loses its magnetising power and become weak in a duration of time.

Answer 2

It is demagnetized when heated strongly, thrown from a height or hammered.