Why is Iron bar Attracted to Either end of Magnet
Most recent answer: 02/28/2015
- rdh (age 7-)
gv, ca, usa
The iron bar is filled with magnetic domains. Each is like a little magnet, but usually they point all different directions That means that their outside magnetic fields pretty much cancel, so the bar isn't a magnet itself.
When the iron is near a permanent magnet, in which the domains are lined up, some of the domain magnetizations in the bar swing around and point in the low-energy direction. That's the direction that gets pulled in toward the magnet, to lower its energy even more. that works at either end, since the domains align whichever way works best at that end.
The other permanent magnet, however, has pretty much permanently aligned domains. If they're lined up the right way to get pulled in, it does. If they're lined up the other way, they don't turn around inside the magnet. Instead they get pushed away.
(published on 02/28/2015)