1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electrons and magnetic fields

  1. Feb 24, 2016 #1
    is it correct that if free floating electrons enter a magnetic field @ a right angle to the field they will take a
    circular orbit around such field?
     
  2. jcsd
  3. Feb 24, 2016 #2

    jfizzix

    User Avatar
    Science Advisor
    Gold Member

    That is what the Lorentz force law would tell us:
    [itex]\vec{F}=q \vec{v}\times\vec{B}[/itex]

    The Force a free floating electron would experience due to the magnetic field would be perpendicular to both its current velocity and the direction of the magnetic field. Since this force is constant in magnitude and always perpendicular in direction, you can expect the electron to (at least to a good approximation) take a circular trajectory while inside this constant magnetic field.

    I've heard more fully relativistic treatments of the electron trajectory aren't quite this simple, but it remains a good approximation, so long as the electron isn't moving close to the speed of light.
     
  4. Feb 25, 2016 #3

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    They don't do an orbit "around" a field, they would follow a circular path in the field. It cannot be a full circle with a static homogeneous field however, if the electrons enter it at some point they have to leave it again (because they would arrive at the same point of entrance again later).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Electrons and magnetic fields
Loading...