# A potentiometer consist of a wire of length 4 m and resistance 10 ohm. It is connected to a cell of emf 2 V . The potential difference per unit length of the wire will be? 1) 5 V/m 2) 2 V/m 3) 0.5 V/m 4) 10 V/m

Jan 31, 2018

$\frac{E}{L} = 0.5 \text{V/m}$
The actual $R = 10 \setminus \Omega$ value doesn't affect the result. It only limits the total electric current flowing through the full length potentiometer.
$\frac{E}{L} = \text{emf (V)"/"length (m)"= (2"V")/(4"m")=0.5 "V/m}$.