Why should the balance point be obtained in the middle one third portion of the meter bridge wire, while finding the balancing lenght?

The balance point is obtained in the middle of the bridge wire for the following reasons:

➡When the balance point is in the middle of the bridge wire, the resistance in the four arms P, Q, R and X become of the same order and consequently the bridge becomes more sensitive.

➡If some errors occurs in locating the balance point, the error in the measured value of the resistance will be comparatively smaller.

➡The error due to end resistance is reduced.