Question
A steel wire of cross-sectional area $0.5 \mathrm{~mm}^2$ is held between two fixed supports. If the wire is just taut at $20^{\circ} \mathrm{C}$, determine the tension when the temperature falls to $0^{\circ} \mathrm{C}$. Coefficient of linear expansion of steel is $1.2 \times 10^{-5}{ }^{\circ} \mathrm{C}^{-1}$ and its Young's modulus is $2.0 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$.
