In a potentiometer experiment, the balancing with a cell is at length 250 ~cm . In shunting the cell with a resistance of 2 , the balancing length becomes 125 ~cm . The internal resistance of the cell is

Step-by-step solution

Given, balancing length with emf of cell, l₁=250 ~cm Balancing length with cell and shunt resistance, l₂=125 ~cm Shunt resistance, R=2 Let r be the internal resistance of cell. Then, using relation, r=R ( l₁ l₂ -1 ) By substituting the values, we get r=2 ( 250 125 -1 )=2