a) Two cells of emf E1 and E2 have their internal resistances r1 and r2, respectively. Deduce an expression for the equivalent emf and internal resistance of their parallel combination when connected across an external resistance R. Assume that the two cells are supporting each other.
(b) In case the two cells are identical, each of emf E = 5 V and internal resistance r = 2 Ω , calculate the voltage across the external resistance R = 10 Ω.
