Question

potentiometer is 10 m long. It has a resistance of 20 Ω. It is connected in series with

a battery of 3 V and a resistance of 10 Ω. What is the potential gradient along with wire?

Answer 1

As current in the circuit would be :

$I = \cfrac{V}{R+r}$

$I= \cfrac{3}{20+10} = 0.1 A$

potential drop across wire :

$V’= IR =0.1 (20)= 2V$

So potential gradient would be :

$\cfrac{V’}{L}=\cfrac{2}{10}=0.2 V/m$