Re: Behaviour of a magnet after it has been broken

It depends greatly on how the magnet is originally magnetized. In the description of the magnet in your question it should NOT have repelled each other, as you yourself surmised, so that tells me that the magnet is magnetized differently than what you described.

For instance, take this magnet:

[N S]
[N S]
[N S]
[N S]
[N S]
[N S]

and break it along the short axis so that now you have two magnets that are like this:

[N S]
[N S]
[N S]
*break*
[N S]
[N S]
[N S]

and these two pieces certainly will repel.

Some commonly used magnets these days are magnetized is stripes, especially magnets that are made for refrigerators. (They are done this way so that the magnetic field at relatively large distances from the magnet is more or less zero.) Sort of like this:

[NSNSNSNSN]
[NSNSNSNSN]
[NSNSNSNSN]
[NSNSNSNSN]
[NSNSNSNSN]

The behavior of these magnets after cutting also depends on how they are cut. Try it!!

John Link, MadSci Physicist