Question

High-voltage power lines are a familiar sight throughout the country. The aluminum wire used for some of these lines has a cross-sectional area of 5.00 10-4 m2. What is the resistance of ten kilometers of this wire?

Answer 1

Answer:

Resistance, R = 0.564 ohms

Explanation:

Area of cross section of the aluminium wire, $A=5\times 10^{-4}\ m^2$

Length of the wire, L = 10 km

Resistivity of the aluminium wire is, $\rho=2.82\times 10^{-8}\ \Omega-m$

The resistivity of a wire is given by the relation as follows :

$R=\rho\dfrac{L}{A}\\\\R=2.82\times 10^{-8}\times \dfrac{10\times 10^3}{5\times 10^{-4}}\\\\R=0.564\ \Omega$

So, the resistance of the wire is 0.564 ohms.