Why is it important to vary the current and take multiple readings while verifying Ohm's law?
ATo prove that the battery has no internal resistance
BTo check whether potential difference changes randomly
CTo test whether $V$ remains proportional to $I$ over different values
DTo ensure the ammeter reads zero before every observation
Answer & Solution
Correct answer: C. To test whether $V$ remains proportional to $I$ over different values
Ohm's law is not established from a single reading; it requires checking the relation between $V$ and $I$ for different values. By varying the current with the rheostat and observing corresponding voltmeter readings, one tests whether $V/I$ stays constant. Option A is unrelated, and option D is not the purpose of taking multiple readings.
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