How is voltage defined in electrical terms?

• A. Electrical pressure, measured in volts
• B. Electrical current flow
• C. Resistance to current flow
• D. Power consumption

Answer: (A)

Voltage is the electrical potential difference that pushes charges to move. It acts like water pressure in a system, providing the driving force that makes current flow when a complete path is available. The volt is the unit, defined as one joule of energy per coulomb of charge. This driving force is not the current itself (which is the rate of charge flow, measured in amperes), nor is it resistance to that flow (measured in ohms), nor power consumed (watts). Ohm’s law ties them together: voltage equals current times resistance. Voltage can exist even without current, such as across an open circuit, but the potential difference remains and would drive current if the circuit were closed.