Properties Of Matter

Each of three blocks \(\mathrm{P}, \mathrm{Q}\) and \(\mathrm{R}\) shown in figure has a mass of \(3 \mathrm{~kg}\). Each of the wires \(\mathrm{A}\) and \(\mathrm{B}\) has cross-sectional area \(0.005 \mathrm{~cm}^2\) and Young's modulus \(2 \times 10^{11} \mathrm{~N} \mathrm{~m}^{-2}\). Neglecting friction, the longitudinal strain on wire \(B\) is ________ \(\times 10^{-4}\). (Take \(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\))