Question

Calculate the area of cross section of a wire of length $2$ $m$, resistance $46$ $\Omega$ and resistivity $1.84\times {10}^{-6}$ $\Omega m$.

Answer 1

$R=\frac{\rho l}{A}$
$\Rightarrow A=\frac{\rho l}{R}$
$\Rightarrow A=\frac{1.84\times {10}^{-6}\times 2}{46}$
$\Rightarrow A=8\times {10}^{-8}$ $m^2$