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
