Question

In an experiment of potentiometer for measuring the internal resistance of a primary cell a balancing length l is obtained on the potentiometer wire when the cell is in open circuit. Now the cell is short circuited by a resistance r. If r is to be equal to the internal resistance of the cell the balancing length on the potentiometer wire will be

Answer 1

Explanation:

If a cell of emf E and internal resistance r, connected to an external resistance R, then the circuit has the total resistance (R+r).