Question

A potentiometer consists of a wire of length 4 m and resistance $10\, \Omega$ It is connected to a cell of e.m.f. 2 V. The potential difference per unit length of the wire will be

• A. 5 V/m
• B. 2 V/m
• C. 0.5 V/m
• D. 10 V/m

Answer 1

Answer: (C)

0.5 V/m

Answer 2

$i=\frac{2}{10}$
$i=0.2 \, A$
$\frac{R}{l}=\frac {10}{4}$
Potential difference per unit length
$\, \, =0.2 \times (\frac {10}{4})$
$= 0.5\, V/m$

So, the correct option is (C): 0.5 V/m