Question

A potentiometer wire is 10 m long and has a resistance of 10 ohm. It is connected to a battery of emf 5 V and internal resistance 2 ohm. calculate the potential gradient along the wire.

Answer​

Answer 1

Given,

Length of wire , l = 10 m.

Resistance of wire , R = 10 ohm.

Emf of the battery = 5V

internal resistance = 2 ohm.

We need to find potential gradient,

Potential gradient = $\frac{IR}{l}$

Here,  

current flowing in the potentiometer wire , I = $\frac{E}{R+r}$

= $\frac{5}{10+2}$

= $\frac{5}{12}$

Potential gradient = $\frac{IR}{l}$

= $\frac{5}{12}*\frac{10}{10}$

= $0.41666 V m^{-1}$

= $0.417 V m^{-1}$

Answer 2

POTENTIOMETER :

Answer : 0.416 V/m

Explanation :

Refer the attached picture.