Physics Question from JEE Main 2023 · 13 April, Shift 1

The elastic potential energy stored in a steel wire of length $20 \, \text{m}$ stretched through $2 \, \text{cm}$ is $80 \, \text{J}$. The cross sectional area of the wire is _____ $\text{mm}^2$. (Given, $y = 2.0 \times 10^{11} \, \text{N m}^{-2}$)