${d^2} = \frac{{4 \times 400 \times {{10}^{ - 6}}}}{{\pi \times 379}} = 0.336 \times {10^{ - 6}} \times 4$
$d = 2\sqrt {0.336} \times {10^{ - 3}}M \simeq 1.16\,mm$
$(I)$ the loss of gravitational potential energy of mass $M$ is $Mgl$
$(II)$ the elastic potential energy stored in the wire is $Mgl$
$(III)$ the elastic potential energy stored in wire is $\frac{1}{2}\, Mg l$
$(IV)$ heat produced is $\frac{1}{2}\, Mg l$
Correct statement are :-