A current of 0.01 A flows through a potentiometer wire of cross section area `10^(-6)m^(2)`. If the specific resistance of the potentiometer wire is `10^(-7)` ohm-m, then the potential gradient will be

Options

A. `10^(-1) V//m`
B. `10^(-3) V//m`
C. `10^(-2) V//m`
D. `0.5xx10^(-2) V//m`

Answer

B

Explanation

`R= (eL)/(A)=(10^(-7)xxL)/(10^(-6))= 0.1 L Omega because V= 1 R`
`therefore (V)/(L)=(0.01xx0.1 L)/(L)= 10^(-3) V//m`