Question

The resistance of a wire is 10 Ω at 27°C. Find its resistance at −73°C. The temperature coefficient of resistance of the material of the wire is 1.70 × 10⁻⁴°C⁻¹.

Answer 1

We are given:

Initial resistance R₁ = 10 Ω at temperature T₁ = 27^∘C​

 Final temperature T₂ = −73^∘C

R₂​ = R₁​[1 + α (T₂ ​− T₁​)]

ΔT = T₂ ​− T₁ ​= −73 − 27 = −100^∘C

R₂​ = 10[1 + (1.70 × 10⁻⁴) × (−100)]

= 9.83 Ω