1. A copper rod of length L = 10 cm and cross-sectional area A = 2 mm² has a resistance of 8.5 × 10⁻⁴ Ω across its ends. Find the resistivity ρ of copper.
(A) 4.25 × 10⁻³ Ω/m
(B) 4.25 × 10⁻¹ Ω/m
(C) 42.5 Ω/m
(D) 1.7 × 10⁻⁴ Ω-m
(E) 1.7 × 10⁻⁸ Ω-m

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