1. Velocity Selector Bout                                 v E +        
                   
The magnetic field is uniform inside the dashed-line region. What speed will allow the proton to pass undeflected through region of uniform electric field?

2. Velocity Selector Bout                                 v v E + +        
                   
When the electric and magnetic forces balance then the charge will pass straight through.

3. Also, we simplified the calculation by making perpendicular to
Velocity Selector
Bout                 v v E + +        
                   
This only works if the electric and magnetic fields are perpendicular and oriented so that is antiparallel to
Also, we simplified the calculation by making perpendicular to