Which statement best describes a linear resistor's V-I relationship?

• A. The ratio V/I changes with current.
• B. The ratio V/I remains constant as V and I vary.
• C. Voltage is independent of current.
• D. Resistance depends on frequency.

Answer: (B)

In a linear resistor, Ohm's law holds with a constant resistance. The voltage across the resistor is proportional to the current through it, so the ratio V over I is always the same value, equal to R, no matter what the actual V and I are (as long as you stay in the resistor’s linear operating range). This means the V–I relationship is a straight line through the origin, with slope R.

That’s why the statement that the ratio V/I remains constant as V and I vary is the best description: it captures the constant, fixed resistance that defines a linear resistor. The idea that V/I changes with current would imply nonlinearity; the claim that voltage is independent of current contradicts V = IR; and saying resistance depends on frequency isn’t part of the ideal resistor model (frequency effects would come from parasitics or other components).