Two batteries of emf ${\epsilon }_1\text{ and }{\epsilon }_2 ({\epsilon }_2>{\epsilon }_1)$ and internal resistances ${\mathrm{r}}_1 \mathrm{and} {\mathrm{r}}_2$ respectively are connected in parallel as shown in the figure.

1. The equivalent emf ${\mathrm{\epsilon }}_{\mathrm{eq}}$ of the two cells is between ${\epsilon }_1\text{ and }{\epsilon }_2.\text{ i.e, }{\epsilon }_1<{\epsilon }_{eq}<{\epsilon }_2$

2. The equivalent emf ${\mathrm{\epsilon }}_{\mathrm{eq}}$ is smaller than ${\mathrm{\epsilon }}_1$

3. The ${\mathrm{\epsilon }}_{\mathrm{eq}}$ is given by ${\epsilon }_{eq}={\epsilon }_1+{\epsilon }_2$ always

4. ${\mathrm{\epsilon }}_{\mathrm{eq}}$ is independent of internal resistances ${\mathrm{r}}_1 \mathrm{and} {\mathrm{r}}_2$