Answer:
0.635 m
Explanation:
When calculating the resistance R of a wire, we need its length(l), its cross-sectional area (A) and the resistivity of the material(ρ). The resistance of a wire is given by the equation:
Resistance (R) = Resistivity(ρ) × length (l) / cross-sectional area (A)
For a 12 guage wire,
Resistivity (ρ) = 1.724 × 10 ⁻⁸ ohm m, length (l) = 400 ft = 121.92 m,
Diameter (d) = 0.00205232, cross-sectional area (A) = πd²/4 = π(0.00205232)²/4 = 3.31 × 10 ⁻⁶ m²
[tex]R=\frac{\rho l}{A}=\frac{1.724*10^{-8}*121.92}{3.31*10^{-6}} =0.635m[/tex]
