Two point charges of equal magnitude Q are held a distance d apart. Consider only points on the line passing through both charges. (a) If the two charges have the same sign, find the location of all points (if there are any) at which (i) the potential (relative to infinity) is zero (is the electric field zero at these points?), and (ii) the electric field is zero (is the potential zero at these points?).

Video transcript

Hey everyone in this problem we have two charged particles carry the same kind of charge the same magnitude. Their separation is X. For an access passing through both particles were asked to determine all points where the electric potential is zero. Okay, we can take the electric potential to be zero at infinity. And then we're asked will the electric field B0 at the points we have identified. Alright, so let's start with the electric potential. Now recall the electric potential. V me written 1/4 pi epsilon? Not Okay. Times the sum of the ratio of the charge to our So we have Q one over R one plus Q two Over R two. Okay, because we have two different charges now we are told that our charges have the same. They're the same kind. OK, so same sign and they have the same magnitude. Okay, so that means that Q1 Is equal to Q two. Alright, well if Q one is equal to Q two Then this is going to be non-0. Okay, Q one equals Q two. So this term is not zero. Right? The charges are going to add up. They're going to become either greater positive or greater negative depending on whether they're positive or negative charges. Okay, so that means that the potential is never going to be zero. Okay, we don't have any this term inside the brackets can't be zero. Okay, we know that 1/4 pi epsilon not is not going to be zero. And so when we multiply we are not going to get an electric potential V That is zero. Hm. Alright. So we've done the first part of the question. The second part is asking, will the electric field B zero at that point while we haven't identified any point? Okay. And so our solution here is going to be C. V. Cannot be zero. And there was no point specified to look at the electric field. That's it for this one. Thanks everyone for watching. See you in the next video.