engineering physics MCQ #928

The resistivity of a material is 1.7 * 10^-8 ohm-m at 20°C. If its temperature coefficient is 0.0039 /°C, its resistivity at 100°C is

engineering physics MCQ #928

  1. Question 1

    Q1. The resistivity of a material is 1.7 * 10^-8 ohm-m at 20°C. If its temperature coefficient is 0.0039 /°C, its resistivity at 100°C is

    • A) 2.28 * 10^-8 ohm-m
    • B) 1.7 * 10^-8 ohm-m
    • C) 2.5 * 10^-8 ohm-m
    • D) 3 * 10^-8 ohm-m

    Answer: 2.28 * 10^-8 ohm-m

    Explanation: Using ρ = ρ0 (1 + α(T - T0)), where ρ0 = 1.7 * 10^-8, α = 0.0039, T = 100, T0 = 20, we get ρ = 1.7 * 10^-8 (1 + 0.0039 * 80) = 2.28 * 10^-8 ohm-m