Question

A silver wire has a resistance of 2.1 W at 27.5°c, and a resistance of 2.7 W at 100°C. Determine the temperature coefficient of resistivity of silver.

Answer 1

R_t1 = R_27.5 = 2.1Ω and

R_t2 = R₁₀₀ = 2.7Ω

Applying the relation

\(α=\frac{R_{t2}-R_{t1}}{R_{t1}\times(t_2-t_1)}\) = \(\frac{2.7-2.1}{2.1\times72.5}=\frac{0.7}{2.1\times62.5}\)

a = 0.0039°C^-1