The resistance of a conductor is kept constant. If the potential difference across it is doubled, what happens to the current through it? Justify your answer.
Generated by claude-sonnet-4-6 · 2026-06-26 01:07 · grounding rag
Model Answer
According to Ohm's law, $I = \dfrac{V}{R}$.
Since resistance R is constant, current I is directly proportional to potential difference V.
If V is doubled, the current through the conductor will also double.
Justification: $I = \dfrac{V}{R}$. If V becomes 2V (and R is unchanged), then new current $I' = \dfrac{2V}{R} = 2I$.
Source: Chapter 11 (Electricity), Section 11.4 – Ohm's Law
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Explanation
- Examiners expect you to state Ohm's law (or its formula), identify the proportional relationship between V and I (with R constant), and show the doubling effect — either in words or with a brief calculation.
- Writing $I' = 2V/R = 2I$ earns full marks efficiently.
- Don't forget the condition: resistance (and temperature) must remain constant for Ohm's law to apply.