Two point charges +Q and -Q are placed at a distance r apart. The electric potential at the midpoint between them is:

Core Concept

Electric potential is a scalar quantity, and the total potential at a point is the algebraic sum of the potentials due to each charge. At the midpoint between +Q and -Q, the potential due to +Q is positive (V+ = kQ/(r/2)) and the potential due to -Q is negative (V- = -kQ/(r/2)). The total potential is V = V+ + V- = kQ/(r/2) - kQ/(r/2) = 0.