Question

Three cells, each of emf E but internal resistances 2r, 3r and 6r are connected in parallel across a resistor R. Obtain expressions for (i) current flowing in the circuit, and (ii) the terminal potential difference across the equivalent cell.

Two cells of emf E₁ and E₂ and internal resistances r₁ and r₂ respectively, are connected in parallel, with their terminals of the same polarity connected together. Obtain an expression for the equivalent emf of the combination.

Two cells of emf E each and internal resistances r and 2r are connected in parallel as shown in the figure. The equivalent emf of the combination is :

Two identical cells send the same current in 2 ohm resistance, whether connected in series or in parallel. The internal resistance of the cell should be