A Storage battery of emf 8.0V and internal resistance 0.5$\mathrm{\Omega }$ is being charged by a 120V dc supply using a series resistor of 15.5$\mathrm{\Omega }$ . What is the terminal voltage of the battery during charging ?

E=V−e=120−8=112V

$\text{ Current in the circuit }I=\frac{\text{ Effective emf }}{\text{ Total resistance }}$

$=\frac{\mathrm{E}}{\mathrm{r}+\mathrm{R}}=\frac{112}{0.5+15.5}=7\mathrm{A}$

The battery of 8V is being charged by 120V, so the terminal potential across battery of 8V will be greater than its emf.

Terminal potential difference

V=E+Ir =8+7(.5) =11.5V