Question

The resistivity of the material of a potentiometer wire is \(5 \times 10^{-6}\,\Omega m\) and its area of cross section is \(5 \times 10^{-6}\,m^2\). If \(0.2\,A\) current is flowing through the wire, then the potential drop per metre length of the wire is

• A. 0.1 Vm\(^{-1}\)
• B. 0.5 Vm\(^{-1}\)
• C. 0.25 Vm\(^{-1}\)
• D. 0.2 Vm\(^{-1}\)
• E. 0.01 Vm\(^{-1}\)

Hint:

Potential gradient = current × resistance per unit length.

Answer 1

The Correct Option is D