The potentiometer

Concepts/Formula used:

Wheatstone bridge:

The condition for no deflection through the galvanometer is

Here, and

Let the potentiometer wire be at l cm from A when there is no deflection through galvanometer.

Let the resistance per cm of the potentiometer wire be be ρ .

Hence, and .

Using the equation when there is no deflection for a Wheatstone bridge/potentiometer, we have

Hence, the free end of the galvanometer must be 16cm from point A.