The potential difference from a point A to a point B in a uniform electric field is positive if

Question

a) actually, the potential difference will be zero.

b) the electric field vectors point perpendicular to the direction from A to B.

c) the electric field vectors point in the direction from B to A.

d) the electric field vectors point in the direction from A to B.

e) None of the above.

Answer 1

c. The electric field vectors point in the direction from B to A.

Answer 2

a) is correct in a boring zero strength electric field. I'm going to assume the strength of the uniform electric field is non-zero making option a) incorrect.

b) could have been correct if the prompt read "there was no potential difference from a point A to a point B". The reason is because the path from A to B would have the same electric potential (a.k.a. voltage) which is consistent with being along a path that is perpendicular to an existing electric field. For better visualization, imagine/Google search about the electric field and electric potential in-betweens of 2 oppositely charged parallel plates or the radial distance away from a point charge. However, the prompt does not say that, thus, b) is incorrect.

c) is the correct option. This is because electric fields point in the direction of decreasing electric potential. This logic is consistent with the mechanics of 2 oppositely charged parallel plates. The electric field lines point out from the positively charged plate to the negative charged plate. From doing lab experiments on a system like this, measuring with a voltmeter, if you place the red measuring prong on the positive plate and the black prong on the negative plate (depending on what power is being supplied to the system), the voltmeter will read some positive potential difference. Thus, c) is the correct option.

d) is the antithesis to option c). Based on the explanation from c), d) cannot be correct.

e) cannot be correct because option c) ended up being the correct choice making e)'s statement null-and-void.

I hope this helps! Message me in the comment section if there is anything confusing about my explanation or if I have said anything wrong!