Potential Difference Definition

Steps:

• Recall that potential difference (p.d.) is the work done to move a unit charge between two points.
• Identify the formula: p.d. = work done / charge.
• Compare options to this formula.
• Eliminate mismatches based on standard electrical equations.

Why C is correct:

• It matches the definition: p.d. (V) = work done (W) / charge (Q), from the fundamental law of electrostatics.

Why the others are wrong:

• A: Voltage × current equals power (P = V × I), not p.d.
• B: Energy / time equals power (P = energy / time), not p.d.
• D: Current × resistance equals p.d. via Ohm's law (V = I × R), but this derives p.d., not defines it.

Final answer: C