Electric potential is defined as electric potential energy per unit charge, also known as voltage. Which option expresses this definition?

• A. electric potential energy per unit charge (voltage)
• B. Electric field vector strength
• C. Rate of charge flow
• D. Current at a point

Answer: (A)

Electric potential is the potential energy a unit charge would have at a point, so it is energy per unit charge. This is what voltage measures: V = U/q, where U is the electric potential energy and q is the charge. The electric field strength is the force per unit charge and is a vector, not a measure of energy per charge. Rate of charge flow and current describe how much charge is moving, not the energy associated with each unit of charge. So the expression that matches the definition is electric potential energy per unit charge (voltage).