Volt as work per unit charge

Steps:

• Voltage (V) is the electric potential difference, defined as work done (W) per unit charge (Q).
• The formula is V = W / Q, where W is in joules (J) and Q is in coulombs (C).
• Thus, 1 volt equals 1 J of work to move 1 C of charge.
• This matches option D directly.

Why D is correct:

• By definition, the volt is the SI unit for potential difference, equal to one joule per coulomb (V = J/C).

Why the others are wrong:

• A: One coulomb per joule inverts the definition, resembling inverse capacitance (farad).
• B: One coulomb per ampere equals one second, the unit of time.
• C: One joule per ampere equals one ohm, the unit of resistance (R = V/I).

Final answer: D