What is the mathematical expression for the electric ptential difference between points A and B when a charged particle is moving a displacement (s) from A to B in an external electric?

Explanation:

Since, as we know, the potential difference 'ΔV' is the difference of between the Potential energy per unit charge U/qo at one point 'B' to Potential energy per unit charge at other point 'A'. It so happens when a test charge 'qo' moves from point A to B, the potential difference becomes the change of potential energy of the system, i.e.

answer: the answer is a