Question

Calculate the total DC resistance of a 100-meter roll of 2.5 mm² copper wire if the resistivity of copper at 20°C is 1.72 x 10⁻⁸ Ω meter.

Answer 1

Answer:

0.688 Ω

Explanation:

We know that resistance of a wire R = ρ  l /A

  resistance = 1.72 x $10^{-8}$ Ω m ( $\frac{100 m}{2.5 * 10^{-6} m^{2} }$ )

                    = 0.668 Ω