Q 11-08-060JEE MainJEE Main 2023 (6 Apr, Shift 1)Easy
A steel rod has a radius of $20\ \text{mm}$ and a length of $2.0\ \text{m}$. A force of $62.8\ \text{kN}$ stretches it along its length. Young's modulus of steel is $2.0\times10^{11}\ \text{N m}^{-2}$. The longitudinal strain produced in the wire is ______ $\times10^{-5}$.
Numerical value type. Enter your answer.
Answer: 25
$$\text{strain}=\frac{F}{AY}=\frac{62800}{3.14\times4\times10^{-4}\times2\times10^{11}}=\frac{62800}{2.512\times10^8}=2.5\times10^{-4}=25\times10^{-5}$$
Solution by Sreeraj P, M.Sc Physics