14. 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 4.9 x 10-4 m2 . What is the resistance of ten kilometers of this wire

The resistance of the aluminium wire is 0.541 ohms

Explanation:

Given:

Cross sectional area of the aluminum wire, A = 4.9 x 10-4 m2

Length of the wire, L = 10 km = 10,000 m

Resistance of the wire = (pL) / A

Where:

p is resistivity of aluminium wire = 2.65 x 10^-8 ohm-m

L is length of the wire

A is cross sectional area of the wire

Substitute these values and solve for resistance of the wire.

Resistance = (2.65 x 10^-8 x 10,000) / (4.9 x 10^-4)

Resistance = 0.541 ohms

Therefore, the resistance of the aluminium wire is 0.541 ohms