A resistance of R draws current from a potentiometer. The potentiometer wire, AB , has a total resistance of `R_(0)`, A voltage V is supplied to the potentiometer. Derive an expression for the voltage across R when the sliding contact is in the middle of potentialmeter wire.

A cell and two resistors R_1 and R_2 are provided to you. Derive an expression for the effective resistance of the circuit in which current is the same in both resistors.

A potentiometer wire of length L and a resistance r are connected in series with a battery of emf E_(0) and resistance 'r_(1)' . An unknown emf E is balanced at a length 'l' of the potentiometer wire. The emf E will be given by

A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery used across the potentiometer wire, has an emf of 2V and negligible internal resistance. The potentiometer itself is 4m long. When the resistance 'R_(1)' , connected across the given cell has values of (i) infinity (ii) 9.5Omega , the balancing length on the potentiometer wire are found to be 3m and 2.85m respectively. The value of internal resistance of the cell is