What length of copper wire (resistivity 1.68 × 10^-⁸ Ω∙m) of diameter 0.15 mm is needed for a total resistance of 15 Ω?

Question

Quizplus · Accepted Answer

To find the length of the wire, use the formula for resistance: R = ρ(L/A), where R is resistance, ρ is resistivity, L is length, and A is the cross-sectional area. First, calculate the area A = π(d/2)^2 = π(0.15×10^-3/2)^2. Then solve for L: L = R*A/ρ = 15*π(0.15×10^-3/2)^2/(1.68×10^-8), which gives approximately 16 m.

What Length of Copper Wire (Resistivity 1