A metallic conductor in a circuit obeys Ohm's law. Which of the following statements is a direct statement of this law?
The current in the conductor is directly proportional to the potential difference across it, provided its temperature remains constant.
The current in the conductor is inversely proportional to its resistance under all conditions.
The resistance of the conductor is directly proportional to its temperature.
The potential difference across the conductor is independent of the current flowing through it.
26 exam-style questions on OCR A A Level Physics Energy, power and resistance, covering Circuit symbols, E.m.f. and p.d, Resistance, Resistivity, and Power. Each one has a worked solution and a mark scheme showing where the marks go.