A steel rod with $y=2.0 \times 10^{11} \mathrm{Nm}^{-2}$ and $\alpha=10^{-5} \mathrm{C}^{-1}$ of length 4 m and area of cross-section $10 \mathrm{~cm}_2$ is heated from $0^{\circ} \mathrm{C}$ to $400^{\circ} \mathrm{C}$ without being allowed to extend. The tension produced in the rod is $\mathrm{x} \times 10^5 \mathrm{~N}$ where the value of x is $\_\_\_\_$