Q. A $10\ m$ long wire of $20\Omega$ resistance is connected with a battery of $3\ volt$ e.m.f. (negligible internal resistance) and a $10\ \Omega$ resistance is joined to it is series. Potential gradient along wire in volt per meter is
A) 0.02
B) 0.3
C) 0.2
D) 1.3
Explanation
(c) Potential gradient $x = \frac{e}{(R + R_{h} + r)}.\frac{R}{L}$
$= \frac{3}{(20 + 10 + 0)} \times \frac{20}{10} = 0.2$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.