Two cells of e.m.f.'s `E_(1) and E_(2)` where `E_(1) gt E_(2)`, are connected in series so as to assist each other, the balancing length is 2.7m . When the cells are connected in series so as to oppose each other, the balancing length is found to be 0.3m . What is the ratio of their e.m.f.'s ?

Options

A. 1.1
B. 1.25
C. 1.5
D. 1.6

Answer

B

Explanation

`(E_(1))/(E_(2))=(l_(1)+l_(2))/(l_(1)-l_(2))=(2.7+0.3)/(2.7-0.3)=(3)/(2.4)=1.25`