Question

anyone can help me to solve this Q...

Answer 1

$\\ Mass(m)= 15 kg\\\\ Poisson's \:ratio= 0.30\\\\young's \:modulus= 12\times 10^{10} Nm^{-2} \\\\g= 10 ms^{-2}$

Data related to wire

$\\ l(length)=2 m\\\\ r=1 mm\\\\ r= 1\times10^{-3}$

$\text{ change in length } \\\delta l= \frac{mgl}{πr^{2}E}\\\\= \frac{15 \times 10 \times 2}{π \times 10^{-3} \times 12 \times 10^{10}}\\\\ \boxed{\blue{\bold{\large{\delta l= 7.957 \times 10^{-7} m}}}}$

$\sigma =\frac {l \times \delta D}{\delta l \times D}\\\\\delta D =\frac{ \sigma D\times \delta l }{l}\\\\\delta D = \frac{0.3\times 2\times 10^{-3}\times 7.957 \times 10^{-7}}{2}\\\\ \boxed{\red{\large{\bold{\delta D = 2.3871\times 10^{-10} m}}}}$