Physics - Current Electricity Question with Solution | TestHub

In potentiometer experiment, the balancing length is $8\mathrm{m}$ when two cells $E_1$ and $E_2$ are joined in series. When two cells are connected in opposition the balancing length is $4\mathrm{m}$. The ratio of the e.m.f. of the two cells $\left(\frac{E_1}{E_2}\right)$ is