Ohm's law states that, at constant temperature, the current through a conductor is
Correct answer: B. directly proportional to the potential difference across it
- A. inversely proportional to the potential difference across it
- B. directly proportional to the potential difference across it
- C. independent of the potential difference
- D. proportional to the square of the potential difference
Explanation
A graph of current against voltage for an ohmic conductor is a straight line through the origin whose gradient is the reciprocal of the resistance. The condition of constant temperature matters, since a filament lamp heats up as the current rises and its graph curves. Semiconductor diodes are non ohmic for a different reason, conducting in one direction only.
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About Steady Current
Steady current is the continuous flow of charge at a constant rate through a conductor. The topic covers current, charge, potential difference, resistance, Ohm's law, resistivity and electrical power, along with series and parallel circuits, while distinguishing conventional current direction from electron motion.
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