Question

A potentiometer has uniform potential gradient across it. Two cells connected in series $\left(i\right)$ to support each other and $\left(ii\right)$ to oppose each other are balanced over $6$m and $2$m, respectively on the potentiometer wire. The emf's of the cells are in the ratio of.

• A. $1:2$
• B. $1:1$
• C. $3:1$
• D. $2:1$

Answer 1

The correct option is D $2:1$

We know that in potentiometer $E\left(emf\right)\propto l\left(lengthofpotentiometerwire\right)$

$\frac{E_1}{E_2}=\frac{l_1+l_2}{l_1-l_2}=\frac{(6+2)}{(6-2)}=\frac{2}{1}$