A potentiometer wire has a uniform potential gradient. The specific resistance of the material of the wire is $10^{-7}$ ohm-m, the current passing through it is 0.1 A and its cross-sectional area is $10^{-6} m^2$. What is the value of the potential gradient?

$10^{-2} Vm^{-1}$

The correct answer is Option (3) → $10^{-2} Vm^{-1}$

The potential gradient (λ) is -

$λ=\frac{V}{L}=\frac{I×R}{L}$ [By ohm's law]

where,

I = Current in the wire

R = Resistance of the wire

L = Length of wire

A = Area of cross - section

$∴λ=\frac{I×ρ}{A}=\frac{0.1×10^{-7}}{10^{-6}}$

$=10^{-2}V/m$