Question

In a potentiometer arrangment, a cell of emf 1.25 V gives a balance point at 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 ?

Answer 1

Here, `epsilon_(1) = 1.25 V , l_(1) = 35.0 cm, epsilon_(2) = ? , l_(2) = 63.0 cm`
As `epsilon_(2)/epsilon_(1) = l_(2)/l_(1) or epsilon_(2) = (epsilon_(1) xx l_(2))/l_(1) = (1.25 xx 63)/35 = 2.25V`