Question: how to calculate potential difference from charge?
Answer: The potential difference between points A and B, VB − VA, defined to be the change in potential energy of a charge q moved from A to B, is equal to the change in potential energy divided by the charge, Potential difference is commonly called voltage, represented by the symbol ΔV: ΔV=ΔPEq Δ V = Δ PE q and ΔPE = qΔV.