Question

In Figure below, an electron accelerated from rest through potential difference V1=0.955 kV enters the gap between two parallel plates having separation d = 18.2 mm and potential difference V2= 160 V. The lower plate is at the lower potential. Neglect fringing and assume that the electron's velocity vector is perpendicular to the electric field vector between the plates. In unit-vector notation, what uniform magnetic field allows the electron to travel in a straight line in the gap?

| | -----------------
| | |
| X | ----------> | d V2
| | |
V1 ----------------

Y
|
|
|_____ X

Answer 1

Dont you want the force on the electron from the 160V plates to equal the force from the magnetic field?
I will be happy to critique your thinking.