In a potentiometer the balancing length of the wire is found to be `2.5 m` for a cell of e.m.f. `1.5V`. Find the balancing length of the wire fore another cell of e.m.f. `1.2 V` on the same potentiometer.

Explanation

Given : `E_(1) = 1.5 V, E_(2) = 1.2 V, l_(1) = 2.5 m`
As we know ,
`(E_(1))/(E_(2)) = (l_(1))/(l_(2))`
`l_(2) = (E_(2))/(E_(1)) xx l_(1)`
` = (1.2 xx 2.5)/(1.5)`
`= 0.4 xx 5`
`l_(2) = 2 m`