The primary principle behind the working of a potentiometer is that the potential drop across any length of a uniform wire carrying a constant steady current is: MCQ with Answer and Explanation

The primary principle behind the working of a potentiometer is that the potential drop across any length of a uniform wire carrying a constant steady current is:
A. Inversely proportional to its length.
B. Independent of its length.
C. Directly proportional to its length.
D. Directly proportional to the square of its length.
Answer: Option C
Solution (By JKExamLibrary)
A potentiometer uses a long wire of uniform cross-section and composition. When a constant steady current flows through it, Ohm's law (V = IR) and the resistance formula (R = rhoL/A) combine to give V = I(rho/A)L. Since I, rho, and A are constant, the potential drop V is strictly directly proportional to the length L of the wire.

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This question belongs to: Science Physics
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This question belongs to: Science Physics
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This question belongs to: Science Physics