Q. A $2\ volt$ battery, a $15\ \Omega$ resistor and a potentiometer of 100 cm length, all are connected in series. If the resistance of potentiometer wire is $5\Omega,$ then the potential gradient of the potentiometer wire is
A) $0.005\ V/cm$
B) $0.05\ V/cm$
C) $0.02\ V/cm$
D) $0.2\ V/cm$
Explanation
(a) Potential gradient $= \frac{e}{(R + R_{h} + r)}.\frac{R}{L}$
$= \frac{2}{(15 + 5 + 0)} \times \frac{5}{1} = 0.5\frac{V\ }{m} = 0.005\frac{V}{cm}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.