By what factor is the resistance of a copper wire changed when its temperature is increased from 30.0°C to 115°C? The temperature coefficient of resistivity for copper = 3.9 × 10−3 (°C)−1

The resistance of the wire increases by a factor of 1.3315

Explanation:

The relationship between resistance of a wire and its temperature change is given by

R = R₀ (1 + αΔT)

R = Resistance at any other temperature.

R₀ = Resistance at a reference temperature.

α = temlerature Coefficient of resistivity = 3.9 × 10⁻³ (°C)⁻¹

ΔT = difference in twmlerature between the current temperature and the reference temperature = 115 - 30 = 85°C

R = R₀ (1 + (0.0039)(85))

R = R₀ (1.3315)

R = 1.3315 R₀

(R/R₀) = 1.3315

Explanation:

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