What is the unit used to express electromotive force or potential difference?

What is the unit used to express electromotive force or potential difference?

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

Answer: (A)

Voltage measures electromotive force and potential difference. It tells you the energy per unit charge that a source provides or that drops as charges move through a circuit. The volt is defined as one joule per coulomb (1 V = 1 J/C), so a 1-volt potential difference means each coulomb of charge would gain or lose 1 joule of energy as it moves between two points. Electromotive force is the driving force behind current, typically supplied by batteries or generators, and voltage is the unit used to express that driving potential. Other quantities describe different aspects of circuits—amps for current, ohms for resistance, watts for power—so voltage specifically captures the push behind current flow.

Voltage measures electromotive force and potential difference. It tells you the energy per unit charge that a source provides or that drops as charges move through a circuit. The volt is defined as one joule per coulomb (1 V = 1 J/C), so a 1-volt potential difference means each coulomb of charge would gain or lose 1 joule of energy as it moves between two points. Electromotive force is the driving force behind current, typically supplied by batteries or generators, and voltage is the unit used to express that driving potential. Other quantities describe different aspects of circuits—amps for current, ohms for resistance, watts for power—so voltage specifically captures the push behind current flow.