What is the resistance 𝑅R of a 47.1-47.1-m-long aluminum wire that has a diameter of 8.45 mm?8.45 mm

Question

What is the resistance 𝑅R of a 47.1-47.1-m-long aluminum wire that has a diameter of 8.45 mm?8.45 mm? The resistivity of aluminum is 2.83×10−8 Ω·m.

Answer 1

What you need is the formula R = ρl/A

where R = resistance

ρ = resistivity = 2.83×10⁻⁸ Ω·m.

l = 47.1m

A =πD²/4 with the diameter given as 8.45mm = 8.45× 10^-3 m

Let me know if you can work with this.

Answer 2

The formula for resistance is R = ρL/A where ρ is the resistivity in Ω-m.

L is given and cross-sectional A (cylinder) = πd²/4 (I prefer this equation as you are usually given d in engineering and physics problems and you avoid plugging in d for r in the regular formula)

Make sure units mesh: A = π(.00845 m)²/4

Please consider a tutor. Take care.