Q. If the resistivity of a potentiometer wire be $\rho$ and area of cross-section be $A,$ then what will be potential gradient along the wire
A) $\frac{I\rho}{A}$
B) $\frac{I}{A\rho}$
C) $\frac{IA}{\rho}$
D) $IA\rho$
Explanation
(a) Potential gradient $x = \frac{V}{L} = \frac{iR}{L} = \frac{i\left( \frac{\rho L}{A} \right)}{L} = \frac{i\rho}{A}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.