Question

Copper wire of length $3m$ and the area of cross section $1.7\times {10}^{-6}{m}^2$ has a resistance of $3\times {10}^{-2}{m}^2$ ohms. Calculate the resistivity of copper?

Answer 1

$Resistance\left(R\right)=\frac{\rho l}{A}$ where $\rho$ is the resistivity

Here from the given question

$l=3m$ $A=1.7\times {10}^{-6}{m}^2$

$\rho =\frac{RA}{l}$

$\rho =\frac{(3\times {10}^{-2})(1.7\times {10}^{-6})}{3}=1.7\times {10}^{-8}\Omega m$

Keeping the values we get the value of $\rho =1.7\times {10}^{-8}\Omega m$