Q. In a potentiometer experiment, the galvanometer shows no deflection when a cell is connected across $60\ cm$ of the potentiometer wire. If the cell is shunted by a resistance of $6\Omega,$ the balance is obtained across $50\ cm$ of the wire. The internal resistance of the cell is
A) $0.5\ \Omega$
B) $0.6\ \Omega$
C) $1.2\ \Omega$
D) $1.5\ \Omega$
Explanation
(c) $r = \frac{(l_{1} - l_{2})}{l_{2}} \times R^{'} = \left( \frac{60 - 50}{50} \right) \times 6 = 1.2\ \Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.