What is the potential gradient along a wire having an area of cross-section `4xx10^(-4) m^(2)`, if the current flowing through the wire is 0.2 A and its specific resistance is `80xx10^(-6) ohm//m` ?

Options

A. `0.1 V//m`
B. `0.5 V//m`
C. `0.04 V//m`
D. `0.2 V//m`

Answer

C

Explanation

Potential gradient `=(V)/(L)=(IR)/(L)=(I rho L)/(AL)=(I rho)/(A)`
`therefore " Potential gradient " =(0.2xx80xx10^(-6))/(4xx10^(-4))=0.04 V//m`