Q 11-10-007JEE MainAIEEE 2011Easy
A metal rod of Young's modulus $Y$ and coefficient of linear expansion $\alpha$ is held at its two ends such that its length remains invariant. If its temperature is raised by $t\ °$C, the linear stress developed in it is
Answer: (B) $Y\alpha t$
The rod is prevented from expanding by $\Delta L = L\alpha t$, so the compressive strain is $\alpha t$:
$$\text{stress} = Y \times \text{strain} = Y\alpha t$$
Solution by Sreeraj P, M.Sc Physics