Q. In a potentiometer experiment, when three cells A, B and C care connected in series the balancing length is found to be 740 cm. if A and B are connected in series balancing length is 540 cm. then the emf of $E_{A},\ E_{B}and\ E_{C}$ are respectively (in volts)
A) 1,1.2 and 1.5
B) 1,2 and 3
C) 1.5,2 and 3
D) 1.5, 2.5 and 3.5
Explanation
(a) $V_{A} + V_{B} + V_{C} \propto 740\ $
$\ \ \ \ \ \ \ \ \ \ V_{A} + V_{B} \propto 440$
$\ \ \ \ \ \ \ \ \ \ V_{B} + V_{C} \propto 540\ $
Hence $V_{A}:V_{B}:V_{C} = 1:1.2:3.5$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.