Ohm’s law proportionality — voltage vs. current: Doubling the voltage across a fixed resistor will cut the current by half. Evaluate this statement for a linear (ohmic) resistor.

Introduction / Context:Ohm’s law is the foundational relationship between voltage, current, and resistance: V = I * R. Misstatements about proportionality are common in quick reasoning under pressure. This question tests whether doubling the applied voltage across a fixed, linear resistor halves the current, doubles it, or does something else.

Given Data / Assumptions:

• Resistor is linear (ohmic) over the operating range.
• Resistance R is constant with voltage in the scenario.
• Ambient and self-heating effects are negligible for the concept check.

Concept / Approach:From I = V / R, holding R constant means current is directly proportional to voltage. If V is doubled, I must also double, not be halved. The statement in the stem therefore contradicts Ohm’s law for an ohmic resistor. Non-ohmic devices (lamps, diodes) may not follow V/I linearity, but they are not “resistors” in the ideal Ohm’s law sense posed by the question.

Step-by-Step Solution:

Verification / Alternative check:Graphing the I–V curve of a resistor gives a straight line through the origin with slope 1/R. Doubling V moves you to a point with twice the current on the same line—consistent with the direct proportionality.

Why Other Options Are Wrong:

• Correct: Not correct; the correct behavior is doubling, not halving.
• Only correct for non-ohmic devices: The question states “resistor”; non-ohmic devices are outside scope.
• Correct only if temperature rises: Temperature coefficients can change R slightly but not invert proportionality to make current half for doubled voltage.

Common Pitfalls:Confusing series/parallel changes in R with changes in applied V; attributing non-linear device behavior to ideal resistors.

Final Answer:Incorrect.