Q. The current in the primary circuit of a potentiometer is 0.2A. the specific resistance and cross-section of the potentiometer wire are $4 \times 10^{- 7}\Omega$m and $8 \times 10^{- 7}m^{2}$ respectively. Potential gradient will be equal to
A) 0.2 V/m
B) 1V/m
C) 0.3V/m
D) 0.1V/m
Explanation
(d) Potential gradient of a potentiometer
$K = \frac{I\rho}{A} = \frac{0.2 \times 4 \times 10^{- 7}}{8 \times 10^{- 7}}$
$\ \ \ \ = 0.1V/m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.