Question

What is the resistance of a 25.0-m-long piece of 12-gauge copper wire having a 2.053-mm diameter?

Answer 1

The resistance of a wire

$$R=\rho\frac{l}{A}\\ =1.68*10^{-8}*\frac{25.0}{3.14*(2.053*10^{-3}/2)^2}\\ =0.13\:\Omega$$