A potentiometer wire carrying a steady current is 100cm long. When a standard cell of emf 1.5v is connected to balance length if 60cm was obtained. Calculate the emf of a cell that gives a balance length of 80cm
To calculate the emf of a cell that gives a balance length of 80cm, we can use the principle of a potentiometer:
Let the unknown emf of the cell be E' volts.
Using the principle of a potentiometer:
E'/1.5 = (80-60)/100
E' = 1.5 * 0.2
E' = 0.3 volts
Therefore, the emf of the cell that gives a balance length of 80cm is 0.3 volts.