I'm learning about how a current in a wire can create a magnetic field, here is the diagram I see: enter image description here

My question is about how the magnetic field effects things in space.

If there was a magnetic material that was a certain distance d away from the wire and then current goes through the wire, would the material orbit around the wire at distance d forever?


After reading the responces, I understand that it would not rotate around the lines, but it would align to them as Claudio mentions.

My initial question actually arised after watching this video. So now I am going to change my question a little.

If you put a perfect circle of iron fillings in space around a wire, and allow current to flow through the wire, would they orbit around the wire?


2 Answers 2


The magnetic field generated by an electric current is highly non uniform. The magnetic field of a permanent small magnet is also non uniform.

The expected behavior in this case is the same of any 2 magnets: they rotate to align the fields and attract each other.

  • $\begingroup$ I see. Do you think you could help answer my new question? $\endgroup$ Commented Mar 15, 2021 at 2:56

The magnetic field lines show the direction of the magnetic field. The separation of the field lines show how strong it is in that region - close field lines means a strong magnetic field and larger separation means a weaker field.

The field can then be used to find the force on a charged particle or on a wire carrying a current using $F=BQv$ where $Q$ is the charge and $v$ is the velocity of the charge. For the wire it's $F=BIL$ where $I$ is the current and $L$ is the length of wire in the field.

The direction of the force in either of the above situations is from 'Flemings Left Hand Rule'.

The magnetic material you mentioned would not necessarily be much influenced by the situation you described. The magnetic field created by the wire has most influence on moving charges, as described above.


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