Question

An electron travels with speed 1.5 times 10⁷ m/s between the two parallel charged plates shown in the figure(Figure 1). The plates are separated by 1.0 cm and are charged by a 200 V battery.  

What magnetic field strength will allow the electron to pass between the plates without being deflected?  Express your answer to two significant figures and include the appropriate units.  

What is the direction of the magnetic field?  

upward  

downward  

into the page  

out of the page

Answer 1