A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4 m long. When the resistance, R, connected acrose the given cell, has values of .
(i) infinity
(ii) 9.5
(A) 0.25
(B) 0.95
(C) 0.5
(D) 0.75