Question

The potentiometer wire AB shown in figure (32-E27) is 50 cm long. When AD = 30 cm, no deflection occurs in the galvanometer. Find R.

Answer 1

The deflections does not occur in galvanometer if the condition is a balanced

wheatstone bridge.

Let Resistance / unit length = r.

Resistance of 30 m length = 30 r.

Resistance of 20 m length = 20 r.