A silver wire has a resistance if 2.1 Ω at 27.5 °C & 2.7Ω at 100 °C. Determine the temperature coefficient of resistivity of silver.

Q: A silver wire has a resistance if 2.1 Ω at 27.5 °C & 2.7Ω at 100 °C. Determine the temperature coefficient of resistivity of silver.

Sol. R_t = R₀ (1 +  α θ)

2.1 = R₀ (1 + α × 27.5 )    …(i)

2.7 = R₀ (1 + α × 100)     …(ii)

Solve equation (i) and (ii)

α = 0.0039 °C ^-1