Question

The diameter of 0 gauge copper wire is 8.252 mm. Find the resistance (in ω) of a 2.40 km length of such wire used for power transmission.

Answer 1

d = diameter of the copper wire = 8.252 mm

r = radius of the copper wire = d/2 = 8.252 mm /2 = 4.126 mm = 0.004126 m

A = area of cross-section of the copper wire = πr² = (3.14) (0.004126)² = 53.5 x 10⁻⁶

L = length of the copper wire = 2.40 km = 2400 m

ρ = resistivity of copper wire = 1.68 x 10⁻⁸

resistance of copper wire is given as

R = ρL/A

inserting the above values in the formula

R = ( 1.68 x 10⁻⁸)(2400)/(53.5 x 10⁻⁶)

R = 0.753 ohm