Question

http://apcentral.collegeboard.com/apc/public/repository/ap09_frq_physics_cem.pdf
On free response E&M. 2., part (f), it says The electrons eventually experience no deflection and move through the bar . I just don;t understand why it eventually do not experience deflection/ I appreciate in advance

Answer 1

I appreciate your help!

Answer 2

I don't know! That is interesting! I'm thinking that somebody on OpenStudy can help! I'm not good with this stuff, yet, though.

I would think they would be deflected all the way through! They might reach a point where they can no longer travel up due to the electric repulsive force and the physical containment... But they would still react to it...

I'm thinking that you would look at the Lorentz force equation from Wikipedia
\(\mathbf{F} = q(\mathbf{E} + \mathbf{v} \times \mathbf{B})\)
and see that there's no reason for the deflection, which I think to be the force on the electron do to the magnetic field, to not exist anywhere through that rectangular bar.

Answer 3

They experience no deflection because an electric field builds up that opposes the action of the magnetic field, as theEric rightely said in:
"They might reach a point where they can no longer travel up due to the electric repulsive force and the physical containment..."

Answer 4

Oh cool, thanks! So there still is the magnetic force, but a countering electric force, too. So, there is no deflection in that sense. :) Thank you, @Vincent-Lyon.Fr

Answer 5

!