How do magnetic fields around connected conductive materials take shape?
Asked by
Zyx (
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December 8th, 2014
Say I put some metal balls in a rubber bag and I feed a wire into the bag to charge the metal balls, will the metal balls react at all? It seems to me like they should repel as they all get an equal charge but I could be wrong about any part of that.
If they do repel and if this would work for any number of metal balls I would like to follow up with this: Is there a way to charge the balls so they attract instead?
Hmmm, maybe I should have started by asking if metal balls can behave like ions.
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7 Answers
I think that while the current supplied by the wire is flowing through the metal balls they will generate a magnetic field in the same way a field surrounds a wire with electricity flowing through it. The field collapses when the voltage is removed and neither the wire nor the balls will be magnetized. I imagine because the current will pass through them as a group, that in the same way it passes between atoms in a wire their magnetism will not repel them.
You might be able to get them to repel each other, since they are electrically conductive:
http://biocircuits.ucsd.edu/outreach/?p=399
You will not be able to get them to electrically attract each other because their conductivity will allow opposite charges to neutralize.
@RocketGuy, Given the mass of metal balls, I cannot imagine how much voltage would be needed to cause repulsion.
Yeah, he’s going to need to be in microgravity (space) to make that work. But I was thinking on a conceptual level.
If current is flowing through a series of metal balls then their respective magnetic fields would line up north-south : north-south : north-south since the current is flowing in the same direction through them all, but the fields would be so weak as to be negligible.
I can see how a series of metal balls would have their magnetic fields line up, but a bag full of these balls would have both parallel and series links. Would balls have magnetic polarities in multiple directions?
Interesting question, @Bill1939, We do know that the current will follow the path of least resistance so most of it will go through the shortest path of points where the balls touch. The line of current will flow between those points within the balls. The shape of the current will mostly be similar to a wire that would pass through those points.
The shape of the resulting magnetic field should correspond to the shape of the current.
And I think the balls that are not conducting the main current will take their magnetic polarity from the ambient field from the line of current.
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