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

Resistance of a wire, `R=(rhol)/(A)`
where `rho` is the specific resistance, l is the length and A is the area of cross section of a wire respectively.
Potential gradient = `(V)/(l)=(IR)/(l)=(I(rhol//A))/(l)=(Irho)/(A)`
`=(0.1Axx10^(-7)Omegam)/(10^(-6)m^(2))=10^(-2)V//m`