Question

The resistance of a wire of length 1 m and cross-sectional area 1 mm² is 1Ω. The specific resistance is

• A. 1 Ω^-m
• B. 10^-6Ω^-m
• C. 10^-3Ω^-m
• D. 0.1 Ω^-m

Answer 1

The Correct Option is B

We use the formula for resistance: \(R = ρ × (\frac L A)\)
Rearranging to solve for resistivity (ρ): \(ρ = R × (\frac AL)\)
Given:
\(R = 1 Ω\),
\(L = 1 m,\)
\(A = 1\ mm² = 1 × 10⁻⁶ \ m²\)
Substitute the values: \(ρ = 1 × (\frac {1 × 10⁻⁶}{1}) = 1 × 10⁻⁶\  Ω·m\)

The correct option is (B): \(10^-6\ Ω-m\)