A silver wire has a resistance of 2.1 Ω at 27.5 °C and a resistance of 2.7 Ω at 100 °C. Then the temperature coefficient of resistivity of silver will be .

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Accepted Answer

(2) 3.9 × 10⁻³ °C⁻¹. Given: R₁ = 2.1 Ω at T₁ = 27.5 °C; R₂ = 2.7 Ω at T₂ = 100 °C. Idea: over a modest range the resistance is linear in temperature, R₂ = R₁[1 + α(T₂ - T₁)], so α = (R₂ - R₁)/(R₁(T₂ - T₁)). R₂ - R₁ = 0.6 Ω and T₂ - T₁ = 72.5 °C. α = (0.6)/(2.1×72.5) = (0.6)/(152.25) = 3.9×10⁻³ °C⁻¹. So the temperature coefficient of resistivity of silver is 3.9×10⁻³ °C⁻¹, a rise of about 0.39% of the resistance per degree.

A silver wire has a resistance of 2.1 Ω at 27.5 °C and a resistance of 2.7 Ω at 100 °C. Then the temperature coefficient of resistivity of silver will be ________.

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