Q. A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is $10^{- 7}\ ohm - meter$ and the current passing through it is $0.1\ ampere;$ cross-section of the wire is $10^{- 6}m^{2}.$ The potential gradient along the potentiometer wire is
A) $10^{- 4}\ V/m$
B) $10^{- 6}\ V/m$
C) $10^{- 2}\ V/m$
D) $10^{- 8}\ V/m$
Explanation
(c) Potential gradient $(x) = \frac{i\rho}{A} = \frac{0.1 \times 10^{- 7}}{10^{- 6}} = 10^{- 2}V/m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.