What is the standard unit of electric potential difference (voltage)?

What is the standard unit of electric potential difference (voltage)?

• A. Ohms
• B. Joules
• C. Amps
• D. Volts

Answer: (D)

The standard unit for electric potential difference is the volt. Voltage measures energy per unit charge, so one volt is the potential difference that would move one coulomb of charge with one joule of energy (V = J/C). In circuits, voltage is what pushes current through resistance, described by Ohm’s law as V = I R, so a one-ampere current through a one-ohm resistor corresponds to one volt. Other units here are for different quantities: ohms measure resistance, joules measure energy, and amps measure current. A volt is the unit that specifically expresses the potential difference driving charge between two points.

The standard unit for electric potential difference is the volt. Voltage measures energy per unit charge, so one volt is the potential difference that would move one coulomb of charge with one joule of energy (V = J/C). In circuits, voltage is what pushes current through resistance, described by Ohm’s law as V = I R, so a one-ampere current through a one-ohm resistor corresponds to one volt. Other units here are for different quantities: ohms measure resistance, joules measure energy, and amps measure current. A volt is the unit that specifically expresses the potential difference driving charge between two points.