Physics - Current Electricity Question with Solution | TestHub

Given, $E_1=1\mathrm{V},{\mathrm{E}}_2=2\mathrm{V},{\mathrm{E}}_3=3\mathrm{V},{\mathrm{r}}_1=1\Omega$${\mathrm{r}}_2=1\Omega$ and ${\mathrm{r}}_3=1\Omega$${\mathrm{V}}_{\mathrm{AB}}={\mathrm{V}}_{\mathrm{CD}}=\frac{\frac{{\mathrm{E}}_1}{{\mathrm{r}}_1}+\frac{{\mathrm{E}}_2}{{\mathrm{r}}_2}+\frac{{\mathrm{E}}_3}{{\mathrm{r}}_3}}{\frac{1}{{\mathrm{r}}_1}+\frac{1}{{\mathrm{r}}_2}+\frac{1}{{\mathrm{r}}_3}}=\frac{1}{\frac{1}{1}+\frac{1}{1}+\frac{1}{1}+\frac{3}{1}}=\frac{6}{3}=2\mathrm{V}$