Question

A potentiometer consists of a wire of length 4 m and resistance 10 Ω. 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

Correct option  (c) 0.5 V/m 

Explanation:

Potential difference per unit length

= 0.2 x (10/4) = 0.5 V/m