1. The problem statement, all variables and given/known data An electron initially at rest is accelerated through a potential difference of V and directed into a region with 1) two parallel plates separated by 20 mm with a potential difference of 20 V between them and 2) a uniform 0.5 T magnetic field which is parallel to the plates. (a) Calculate the minimum V required such that the electron feels no force as it moves through the region between the plates. (b) Why is this just a minimum? 2. Relevant equations Fm= qvb Fe=qE 3. The attempt at a solution My initial thought was that the magnetic force and electric force would oppose each other and we could solve qE = qvB for v and thus the delta V required to accelerate to V. However then it asks why is this a minimum. But I don't think it could work if it was just a minimum because increasing v would increase and give an excess magnetic force, so the electron would feel a force, leading me to think this reasoning is wrong. Could I get some advice for this? For example, it says the electron is directed in to the region, does that means its moving parallel to B?