Fill ups:
A……………………is used to compare e.m.f. of two cells.

What is potentiometer? With the help of circuit diagram, explain how a potentiometer can be used to compare the emf of two primary cells.

Fill ups ………………are materials used to polarise light.

Fill ups DeltaG^@ is related to e.m.f of the cell is……………. .

Explain the principle of a potentiometer. How will you compare the e.m.f. of two primary cells by using potentiometer? Explain with proper circuit diagram.