pretty handy with your right hand, aren't you?juice wrote:yeah
i did that experiment last spring, and you're actually looking at an electron ring. because electrons are charged particles, we use the Lorentz force law [F = q(E + v x B)] to find out how they move. in this experiment, you make B perpendicular to the initial velocity provided by a high voltage between the anode and the cathode (which has a small aperture) so you get a nice halo of electrons. so you're not really directly looking at the magnetic field.
also, helmholtz coils are pretty cool.