question_answer

For comparing the e.m.f.'s of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful                                   [MP PMT 1994]

A)                    The e.m.f. of the standard cell is larger than the E e.m.f.'s of the two cells

B)                    The diameter of the wires is the same and uniform throughout

C)                    The number of wires is ten

D)                    The e.m.f. of the standard cell is smaller than the e.m.f.'s of the two cells