\(\Rightarrow \mathrm{R}=2.4 \mathrm{~m} \Omega\)
Temperature fall in \(10 \mathrm{~s}=20^{\circ} \mathrm{C}\)
\(\Delta \mathrm{R}=\mathrm{R} \alpha \Delta \mathrm{t}\)
\(\alpha=\frac{\Delta \mathrm{R}}{\mathrm{R} \Delta \mathrm{t}}=\frac{-0.6}{3 \times 20}\)
\(=-10^{-2} \mathrm{C}^{-1}\)