n identical cells are joined in series with its two cells A and B in the loop with reversed polarities. Emf of each cell is E and internal resistance r. The potential difference across cell A or B is (Here n > 4)
Three identical cells, each of emf 2 V and unknown internal resistance are connected in parallel.This combination is connected to a 6Ω resistor. The terminal potential difference across each cell is 1.5 V. What is the internal resistance of each cell?