What happens when a bar magnet is cut in half?

Question

What happens when a bar magnet is cut perpendicular to its axis of magnetization?

On searching the internet, there a lot of people who suggest pole reversal occurs and the cut ends repel each other, while there are people who say that they will attract.

Related: https://physics.stackexchange.com/q/1402/50583, in particular the answer by Cem. — ACuriousMind, May 05 '18 at 10:42

score 2 · Answer 1 · edited May 05 '18 at 13:02

2

Take two identical bar magnets. Join the them at opposite poles. Now you have one single bar magnet. "Cut" it through the middle, the magnets attract.

edited May 05 '18 at 13:02

geometrikal

103

answered May 05 '18 at 11:15

my2cts

24,097

score 2 · Accepted Answer · answered May 05 '18 at 12:29

2

Here's the standard image:

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It's pretty much the same thing as putting two regular bar magnets together and then pulling them apart. Cutting a single bar magnet in two before separating its halves doesn't really affect anything as far as the magnetic field's concerned.

answered May 05 '18 at 12:29

Nat

4,640

1

Note that if you cut parallel to the axis of magnetization, the halves do repel each other. Furthermore if you have a nice neodymium magnet and you drop it so that it gets chipped, the fractures seem to usually occur parallel to the magnetic axis so that you can't get the chips to go back on. – rob Jun 01 '18 at 12:20

score 1 · Answer 3 · answered May 05 '18 at 13:07

1

I've done this demo 50 times. I can assure you that the the inside ends attract each other. No pole reversal.

answered May 05 '18 at 13:07

M. Enns

8,747

What happens when a bar magnet is cut in half?

3 Answers3