Question: what is the difference in electrical potential between points a and b. δv=vb-va =?
Answer: ΔV = VB − VA = ΔPE q . The potential difference between points A and B, VB – VA , is thus defined to be the change in potential energy of a charge q moved from A to B, divided by the charge. Units of potential difference are joules per coulomb, given the name volt (V) after Alessandro Volta.