A metallic bar of Young's modulus, $$0.5 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}$$ and coefficient of linear thermal expansion $$10^{-5}{ }^{\circ} \mathrm{C}^{-1}$$, length $1 \mathrm{~m}$ and area of cross-section $$10^{-3} \mathrm{~m}^2$$ is heated from $0^{\circ} \mathrm{C}$ to $$100^{\circ} \mathrm{C}$$ without expansion or bending. The compressive force developed in it is :