Question

with the help of circuit diagram explain how potentiometer is used to compare e.m.f of two cells. ( 3 mark )​

Answer 1

Answer:

Working principle of Potentiometer: When a constant current is passed through a wire of uniform area of cross-section, the potential drop across any portion of the wire is directly proportional to the length of that portion. E1, E2 is the emf of the two cells. 1, 2, 3 forms a two-way key.