series and parallel connection

Five identical cells each of internal resistance 1 Omega and emf 5V are connected in series and in parallel with an external resistance 'R' . For what value of 'R', current in series and parallel combination will remain the same ?

Two conducting wires of the same material and of equal length and equal diameters are first connected in series and then in parallel in an electric circuit. The ratio of the heat produced in series and parallel combinations would be :

Two capacitors of unknown capacitance are connected in series and parallel. The effective capacitance in series and parallel combination are 4 muF to 18muF , respectively . Find the capacitance of unknown capacitors.

Battery & E.M.F||Series & Parallel Connections