Specific resistance of a metal conductor is `4xx10^(-5)Omega`m and its area of cross section is `8 cm^(2)` when 0.2A current passes through the conductor then potential gradient of the conductor is

Options

A. `10^(-1)V//m`
B. `10^(-3)V//m`
C. `10^(-2)V//m`
D. `10 V//m`

Answer

C

Explanation

`rho=4xx10^(-5)Omega m, A =8 cm^(2), I=0.2 A, (V)/(l)=?`
`V=IR `
`V=I.(rho l)/(A)`
`:.(V)/(l)=(I rho)/(A)=(0.2 xx 4 xx 10^(-5))/(8xx10^(-4))=10^(-2)V//m`