Question

Calculate the area of cross section of a wire if its length is $1.0m$ its resistance is $28\Omega$ and resistivity of the material is $1.84\times {10}^{-6}\Omega$

Answer 1

We know: $R=\rho \frac{l}{A}$

where, R is the resistance

$\rho$ is the resistivity

l is the length

and A is the area.

$\Rightarrow A=\rho \frac{l}{R}=1.84\times {10}^{-6}\frac{1}{28}=6.57\times {10}^{-8}{m}^2$