VITEEE 2011 Paper

Where potentiometer is connected across A and B, balancing length →64cm Then
A and C then balancing tength → B cm.
Let the be emf ε1 when connected across A and B
and let emf be ε2 when connected acress B and C.
we know that emf of potentiometer ∝ balancing length.
⇒ε1∝64
ε1−ε2∝8
Let the balancing length be lcm when the potentiometer is connected between B and C.
⇒ε2∝l
using the above three equations we get,
64−l‌‌=8
l‌‌=64−8
l=56cm
Hence the balancing length is 56cm.