Question

A cell can be balanced against `110 cm` and `100 cm` of potentiometer wire, respectively with and without being short circuited through a resistance of `10 Omega`. Its internal resistance is

Answer 1

Here, `l_(1) = 110 cm , l_(2) = 100 cm`,
`R = 10 Omega , r=?`
`r = ((l_(1)-l_(2))/(l_(2))) R = ((110 - 100)/(100)) xx 10 = 1 Omega`