Question

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

Answer 1

`E/L=0.5"V/m"`

Explanation:

The actual `R=10\Omega` value doesn't affect the result. It only limits the total electric current flowing through the full length potentiometer.

The relevant calculation is:

`E/L = "emf (V)"/"length (m)"= (2"V")/(4"m")=0.5 "V/m"`.