How can a magnet can lose it strength?

Answer 1

Several factors can weaken the magnetism in a magnet such as being stored close to heat, strong electrical currents, other magnets, or radiation. Over time magnet materials lose a very small amount of magnetism.

Answer 2

I do not know if they can lose their magnetic energy or not.

Hardly worth spending the time to type that answer then, eh?

If you magnetise e.g. an iron bar by striking it with a magnet, and then orient it (say) East-West and it it hard with a hammer, it will have lost some of its magnetism. Well, it won't have 'lost' it exactly, but it will have become more-or-less re-magnetised in a different orientation which has the same effect.

That is only a partial answer and not quantitative (but at least more informative than the first attempt) but this is a serious and interesting question and deserves a more fulsome and authoritative answer. Sorry I cannot provide it, but I bet Google could ...

Answer 3

Magnets can weaken over time because the magnetic domains comprising the substrate become misaligned. Instead of pointing all in one direction, as they do in a "good" magnet, they point in different directions, with the result that the overall magnetic force is diminished.

Answer 4

Magnets do lose a small fraction of their power over time. To help a magnet retain their power for as long as possible, keep them away from high temperatures and power sources.

Answer 5

Magnets lose their magnetism when they are dropped many times, heated over a flame or hammered many times

Answer 6

Drop the magnet from the table to the floor many times.

Answer 7

magnets can lose its strength by repeated falling down