A potentiometer has uniform potential gradient. The specific resistance of the material of the potentiometer wire is `10^(-7)` ohm-meter and the current passing through it is 0.1 ampere, cross-section of the wire is `10^(-6)m^(2)`. The potential gradient along the potentiometer wire is

Options

A. `10^(-4)` V/m
B. `10^(-6)` V/m
C. `10^(-2)` V/m
D. `10^(-8)` V/m

Answer

C

Explanation

`rho = 10^(-7) Omega m , I = 0.1 A, A = 10^(-6) m^(2)`
`V = IR = (I rhoI)/A`
`rArr V/l = (lrho)/A = (0.1 xx 10^(-7))/10^(-6) = 0.001V//m = 10^(-2) V//m`