What are the advantages of the nll-point method in a Wheatstone bridge ? What additional measurements would be required to calculate `R_("unknown")` by any other method ?

Explanation

The advantage of null point method in a Wheatstone bridge is that it has nothing to do with the resistance of a galvanometer (as no current flows through the galvanometer is balanced condition). We do not need to find currents in the resistances, the galvanometer or its internal resistance. `R_("unknown")` can be calculated by using Kirchhoff.s laws. In this method, we need to find currents in the resistances, the galvanomenter and its internal resistance very accurately.