Ohm's Law Defines Resistance

Steps:

• Recall Ohm's Law: potential difference (V) equals current (I) times resistance (R), or V = I × R.
• Rearrange the formula to solve for resistance: R = V / I.
• Identify that this matches the expression for potential difference divided by current.
• Compare choices to confirm the exact match.

Why C is correct:

• Resistance R is defined by Ohm's Law as R = V / I, where V is potential difference and I is current.

Why the others are wrong:

• A: This is conductance (1/R), the inverse of resistance.
• B: Identical to C but listed separately; C is the designated correct choice.
• D: This is part of the formula for resistance of a wire (R = ρL/A), not the basic definition.

Final answer: C