Question

In a potentiometer experiment the balancing length is 8 m, when the two cells `E_(1)` and `E_(2)` are joined in series. When the two cells are connected in opposition the balancing length is 4m. The ratio of the e.m.f. of two cells `(E_(1)//C_(2))` is
A. `1:2`
B. `2:1`
C. `1:3`
D. `3:1`

Answer 1

Correct Answer - D
`(E_(1))/(E_(2))=(l_(1)+l_(2))/(l_(1)-l_(2))=(8+4)/(8-4)=(12)/(4)=(3)/(1)`