Question:
A steel rail of length $5 \mathrm{~m}$ and area of cross-section 40 $\mathrm{cm}^{2}$ is prevented from expanding along its length while the temperature rises by $10^{\circ} \mathrm{C}$. If coefficient of linear expansion and Young’s modulus of steel are $1.2 \times 10^{-5} \mathrm{~K}^{-1}$ and $2 \times 10^{11} \mathrm{Nm}^{-2}$ respectively, the force developed in the rail is approximately:
$2 \times 10^{7} \mathrm{~N}$
$1 \times 10^{5} \mathrm{~N}$
$2 \times 10^{9} \mathrm{~N}$
$3 \times 10^{-5} \mathrm{~N}$
Question of from chapter.
JEE Main Previous Year Online April 9, 2017
Correct Option: 2
Solution: