List of top Physics Questions on Cells in Series and in Parallel

Two cells of emfs 12 V and 6 V are connected in parallel as shown in the figure. Their internal resistances are \(1\,\Omega\) and \(0.5\,\Omega\) respectively. Calculate the emf and internal resistance of the equivalent cell between points A and B.

Two cells \(\varepsilon_1\) and \(\varepsilon_2\) are connected in opposition to each other as shown in the figure. The cell \(\varepsilon_1\) is of emf \(9\ \text{V}\) and internal resistance \(3\ \Omega\). The cell \(\varepsilon_2\) is of emf \(7\ \text{V}\) and internal resistance \(7\ \Omega\). The potential difference between the points \(A\) and \(B\) is: