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 the resistance of galvanometer does not affect the balance point, there is no need to determine current in resistances and the internal resistance of a galvanometer.
It is easy and convenient method for observer.
The `R_("unknown")` can be calculated applying kirchhoff's rules to the circuit. we would need additional accurate measurement of all the currents in resistances and galvanometer and internal resistance of the galvanometer.