Determine the length of a copper wire that has a resistance of 0.172 $\varOmega$ and cross-sectional area of 7.85 × 10^-⁵ m². The resistivity of copper is 1.72 × 10^-⁸ $\varOmega$. m. A)873 m B)250 m C)78.5 m D)785 m E)6570 m

Question

Quizplus · Accepted Answer

We can use the formula for resistance of a wire, R = (ρL)/A, where R is resistance, ρ is resistivity, L is length, and A is cross-sectional area.

Rearranging the formula to solve for L, we get L = (RA)/ρ.

Substituting the given values, we get:

L = (0.172 x 7.85 x 10^-12) / (1.72 x 10^-8) = 785 meters (approximately)

Therefore, the answer is D) 785 m.

Determine the Length of a Copper Wire That Has a Resistance