A potentiometer has a uniform wire of length 10m and resistance `5 Omega`. The potentiometer is connected to an across a cell of e.m.f. 2 V and internal resistanc `10 Omega`. The reading of voltmeter is

Options

A. 1mV/m
B. 5mV/m
C. 0.1 mV/m
D. 4 mV/cm

Answer

B

Explanation

Potential gradient is ,
`Irho=((E)/(R+R_(h)+r))(R)/(L)=((10)/(5+995+0))=(5)/(10)`
`=5xx10^(-3)V//m = 5 m V//m`