Ten identical cells, each of emf 2 V and internal resistance 0.5 , are connected in series to form a battery. However, two of the cells are connected with reverse polarity. If this battery is connected across an external resistor of 5 , the steady current flowing through the circuit will be

Step-by-step solution

Total number of cells, n = 10 Number of reversed cells, m = 2 When m cells are reversed out of n cells, the effective emf of the series combination is given by: E_ eff = (n - 2m)E = (10 - 2 2) 2 V = 6 2 V = 12 V The internal resistance of the cells is independent of their polarity. Thus, the total internal resistance is: r_ eq = n r = 10 0.5 = 5 The total resistance of the circuit is the sum of the external resistance R and the equivalent internal resistance r_ eq : R_ total = R + r_ eq = 5 + 5 = 10 According to Oh