If the potential gradient along with potentiometer wire is decrease will zero deflection position be obtained at longer or shorter length

If the potential gradient along the potentiometer wire is decreased, then zero deflection position will be obtained at a longer length.

Potential gradient along the wire is V/L , then emf of cell to be measured is given by E = (V/L). lb
Since emf of the cell remains unchanged, so on decreasing potential gradient, the balancing length lb increases.

Regards!