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Why does it seem like a broken magnet's poles flip?

I have experienced that if we break a bar magnet into two pieces and try to bring those broken faces together it gets repelled each other. Why is it so?

consider a bar magnet,

$ NN--------SS $

$NN$ for north pole and $SS$ for south pole.

I broke that into two pieces, So one piece would be

$ NN--SS'$ and another piece would be $'NN--SS$ .( $'$ indicates the broken part).

Now if I bring those two together, $SS'$ of first should attract the $'NN$ of the other. But in the reality it is getting repelled.

or is there any pole exchange occuring? $$NN--------SS$$

gives either $$NN---SS'$$ and $$'SS---NN$$ OR $$SS---NN'$$ and $$NN'---SS$$

so it will repel each other.

Please explain why is this happening?

Edit: The cut has been made perpendicular to the polar axis.

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marked as duplicate by David Z Feb 9 '12 at 18:52

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

I think that the bar magnet in question had a dipole moment perpendicular to its length.. So you broke it parallel to the dipole moment, resulting in repulsion. Then again, it would have spun in your hands and you would have realised that the magnet was not normal.. I see no reason for the broken ends to repel.. –  Manishearth Feb 9 '12 at 16:30
Retry the experiment, this time keeping a reference magnet and comparing poles before and after breakage. You shouldnt see any evidence of pole switching, an d the broken ends should attract. If not, we may have an issue.. –  Manishearth Feb 9 '12 at 16:34
Right now I dont have any bar magnets with me :( Ofcourse we dont get confused with the broken ends bcoz clearly it is visible that which end is broken and which is not. –  Inquisitive Feb 9 '12 at 16:35
Im not saying that you confused the broken ends, im saying that the magnet may not be conventional. Imagine that two different opposite faces of your were north and south. Then think what happens when you break it in the way you described. –  Manishearth Feb 9 '12 at 17:31
I found a similar question physics.stackexchange.com/questions/16708/ posted here by zephyr. But even there the answer is not given. Some one please try this experiment and try to figure out this. remember the magnet is cut perpendicular to the polar axis. –  Inquisitive Feb 9 '12 at 17:49

1 Answer 1

This is a common question due to people being confused about where the poles of their magnets actually are. I'm not going to give a full answer, but there is a good explanation here: http://www.madsci.org/posts/archives/2007-02/1172592509.Ph.r.html

And another similar question from this site: Why does it seem like a broken magnet's poles flip?

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Please try to do the first example in both pages(cut perpendicular to polar axis not parallel to polar axis) and check whether it is satisfying the example they given or not. . Now this is very simple experiment, Once you try you will understand. Ofcourse the second example( cutting parallel to the axis) will work as they mentioned, no doubt. –  Inquisitive Feb 9 '12 at 18:07
Sorry, I'm not going to bother doing an experiment that I know the outcome of. This is all simply explained by you not knowing where the poles of your magnet actually are - if you think otherwise you need to provide some proof. –  user2963 Feb 9 '12 at 18:10
@sree Just because a magnet is shaped like a bar doesnt mean that the polar axis is along the 'long' length of the magnet. The poles can also be on the wider faces of the magnet.. –  Manishearth Feb 9 '12 at 18:29
If it was the case I wouldn't have asked this question. –  Inquisitive Feb 9 '12 at 18:34
@sree Do you have a compass? Does the north of the compass point to what you think is the north of your "magnet" and the south to the south? Or is it confused? –  anna v Feb 9 '12 at 18:50

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