State the working principle of Potentiometer. Explain with the of circuit diagram, how the potentiometer is used to determine the internal resistance of the given Primary cell.In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63.0 cm, what is the emf of the second cell?

Potentiometer - Principle and Applications