Answer:
817.02 x 10⁻⁶ m
Explanation:
L = length of the aluminum wire = 39.0 m
R = Resistance of the wire = 2.10 Ω
ρ = Resistivity of aluminum wire = 2.82 x 10⁻⁸ Ω·m
A = area of cross-section of wire
Resistance of the wire is given as
[tex]R = \frac{\rho L}{A}[/tex]
[tex]2.10 = \frac{(2.82\times 10^{-8}) (39)}{A}[/tex]
A = 5.24 x 10⁻⁷ m²
d = diameter of the wire
Area of cross-section of wire is given as
A = (0.25) πd²
5.24 x 10⁻⁷ = (0.25) (3.14) d²
d = 817.02 x 10⁻⁶ m
