Question
Find out when a 50 m long steel rod of 10 $c m ^2$ cross-section is heated from $0^{\circ} C$ to $50^{\circ} C$ (i) increase in length of rod (ii) if both the ends of the rod are connected to rigid supports, then the force produced in it will know thermal stress. (Given $\alpha=1.2 \times 10^{-5}{ }^{\circ} C ^{-1}$ and $\left.Y =9.6 \times 10^7 N / m ^2\right)$