Answer: the V-I relation is not always unique.
- A Ohm's law always holds
- B the V-I relation is not always unique
- C resistance is independent of temperature
- D current is always proportional to voltage
Correct answer: B. the V-I relation is not always unique
Explanation: One NCERT limitation of Ohm's law is that the V-I relation need not be single-valued: the same V can give more than one I, so the graph is non-linear and multi-valued.
In series, the same current flows through both resistors; in parallel, the current splits between branches and the voltage across each resistor is the same.
Concept context
Ohm's law, resistors, Kirchhoff's laws, Wheatstone bridge, and cells.