Question

Write the relationship between the emf of a cell and its internal resistance

Answer 1

$$\begin{gathered} \mathrm{We}\mathrm{kn}ow\mathrm{that}, \\ \mathrm{E}=\mathrm{V}+\mathrm{Ir} \\ \mathrm{where},\mathrm{E}=\mathrm{emf}\mathrm{of}\mathrm{cell} \\ \mathrm{V}=\mathrm{potential}\mathrm{difference} \\ \mathrm{I}=\mathrm{current} \\ \mathrm{r}=\mathrm{internal}\mathrm{resistance} \\ \mathrm{Ir}=\mathrm{E}-\mathrm{V} \\ \mathrm{r}=\frac{\mathrm{E}-\mathrm{V}}{\mathrm{I}} \\ \mathrm{r}=\frac{\mathrm{E}-\mathrm{IR}}{\mathrm{I}} \end{gathered}$$