If a metallic cube of edge 1 cm is drawn into a wire of diameter 4 mm, then the length of the

wire is :*h*.

Each edge of metallic cube = 1 cm = 10 mm

So volume of metallic cube = ${\left(10\right)}^{3}{\mathrm{mm}}^{3}$ = 1000 ${\mathrm{mm}}^{3}$

Now diameter of wire formed = 4 mm

Then its radius;

*r*= $\frac{4}{2}$ = 2 mm

Since the metallic cube is drawn in to wire, so we have;

Volume of metallic cube = volume of wire

$\Rightarrow 1000={\mathrm{\pi r}}^{2}\mathrm{h}\phantom{\rule{0ex}{0ex}}\Rightarrow 1000=\frac{22}{7}\times {2}^{2}\times \mathrm{h}\phantom{\rule{0ex}{0ex}}\Rightarrow 1000=\frac{88\mathrm{h}}{7}\phantom{\rule{0ex}{0ex}}\Rightarrow \mathrm{h}=\frac{1000\times 7}{88}=79.545$

Therefore the length of the wire is 79.545 mm.

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