Two persons pull a wire towards themselves. Each person exerts a force of 200 N on the wire. Young's modulus of the material of wire is $1 \times 10^{11} \mathrm{~N} \mathrm{~m} \mathrm{~m}^{-2}$. Original length of the wire is 2 m and the area of cross section is $2 \mathrm{~cm}^2$. The wire will extend in length by $\mu \mathrm{m}$.