calculate the resistance of 1 kilometre long copper wire of radius 1 m

1.	calculate the resistance of 1 kilometre long copper wire of radius 1 millimetre stability of copper 1.72 into 10 power minus 8 ohm metre
Answer» $\color{darkblue}\underline{\underline{\sf Given-}}$ Lenght of copper WIRE ${\sf (\ell)=1km\:\implies\:1000m}$ Radius (R) = ${\sf 1mm\:\implies\: 10^{-3}m}$ Resistivity ${\sf (\rho)=1.72×10^{-8}ohm.m}$ $\color{darkblue}\underline{\underline{\sf To \: Find-}}$ RESISTANCE (R) ━━━━━━━━━━━━━━━━━━━━━━━━━ $\color{darkblue}\underline{\underline{\sf Formula \: Used-}}$ $\large\color{violet}\bullet\underline{\boxed{\sf R=\rho\dfrac{\ell}{A}}}$ A = Area = πr² ━━━━━━━━━━━━━━━━━━━━━━━━━━ $\implies{\sf R=1.7×10^{-8}×\dfrac{1000}{π×(10^{-3})^2} }$ $\implies{\sf R=1.7×10^{-8}×\dfrac{10^3}{3.14×10^{-6}}}$ $\implies{\sf R=1.7×10^{-8}\dfrac{10^{3+6}}{3.14}}$ $\implies{\sf R= \dfrac{17}{3.14}}$ $\color{red}\implies{\sf R=5.4\:Ω}$ $\color{darkblue}\underline{\underline{\sf Answer-}}$ Resistance of copper wire is $\color{red}{\sf 5.4Ω}$