What is voltage?

• A. The energy stored in a capacitor
• B. The rate of charge flow
• C. The opposition to current flow
• D. Pressure that pushes electricity through an electrical circuit

Answer: (D)

Voltage is the electrical potential difference that pushes electric charges to move; it’s the driving force behind current. The description that fits this idea best is that voltage is the pressure that pushes electricity through a circuit. In precise terms, a volt equals one joule of energy per coulomb of charge, which is why it acts as the energy-per-charge pushing force. This driving force makes current flow through a conductor according to I = V/R in a simple resistor. The other options mix up different quantities: energy stored in a capacitor is stored energy, not the push; the rate of charge flow is current; the opposition to current flow is resistance. Voltage can exist without current if the circuit isn’t complete.