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I Why doesn't a charge repel a magnetic field in this example?

  1. Jan 13, 2017 #1
    The example:
    An electron is trapped in a magnetic field. The electron travels along a circle in a clockwise path. It's my understanding that there is a magnetic field around the electron also circulating in a clockwise direction perpendicular to it's path. Now if this electron was in a conductor, the conductor would have a magnetic field opposing the original magnetic field. So, why doesn't the electron?

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  2. jcsd
  3. Jan 13, 2017 #2
    Does not the electron perform a spiral as a result of what you are saying?
     
  4. Jan 13, 2017 #3
    It will spiral if it has a parallel component to it's velocity.
     
  5. Jan 14, 2017 #4
    For the case of the loop of wire, the magnetic field inside the loop points in the opposite direction to that outside it. So overall, I don't think it has a force on it.
    The single electron does seem to have a resultant force causing it to spiral, because it is acting like a loop edge-on to the magnetic field.
     
  6. Jan 25, 2017 #5
    On my second point, I don't think I am correct here. The electron has opposite fields above and below it, so presumably these cancel.
     
  7. Jan 26, 2017 #6
    Normally, you neglect the effect of a particle's field on itself. If you had more than one electron, then you would have to consider the effect of the electrons' fields on each other.
     
  8. Jan 26, 2017 #7
    I think the electron did work against its own field when it was accelerated to its present velocity and this energy is now mostly stored in its magnetic field.
     
  9. Jan 27, 2017 #8
    I see now that the magnetic field of the electron is reinforced on 1 side, according to the left hand rule. This makes since for the electron to curve away from that side without experiencing a net repulsion.
     
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