The length of the potentiometer wire is L=10m. The resistance of the potentiometer wire is Rω=5Ω The emf of the cell is E=2.2V The potential difference across a length of l=660cm of the wire is Vl=1.1V. l=660cm=6.6m The potential gradient, K=
Vl
l
K=
1.1V
6.6m
=
1
6
V∕m The total potential drop across the wire Vω is Vω=K×L Vω=
1
6
V∕m×10m=
10
6
V=
5
3
V Current, I=
Vω
Rω
=
5
3
V
5Ω
=
1
3
A The current in the main circuit is also given by I=
