Ohm's law is valid under the condition that the
- conductor length keeps changing
- temperature of the conductor remains constant
- current is always zero
- battery has infinite emf
Show answer and solution
Correct answer: B. temperature of the conductor remains constant
The statement of Ohm's law includes the condition of constant temperature.
If temperature changes, the resistance may change and the proportionality between $V$ and $I$ may no longer hold.