A constant force is applied to a metal wire of length 'L'. Volume of the wire is constant. The extension…
A constant force is applied to a metal wire of length 'L'. Volume of the wire is
constant. The extension produced is proportional to
$\mathrm{L}^{2}$
$\mathrm{~L}^{3}$
$\mathrm{~L}$
$\mathrm{~L}^{-2}$
Solution
let the volume be $\mathrm{V}$ and area $\mathrm{A}$
$\mathrm{Y}=\frac{\mathrm{Fl}}{\mathrm{A} \Delta \mathrm{l}}$
$\Delta \mathrm{l}=\frac{\mathrm{Fl}}{\mathrm{YA}}$
$V=A \times 1$
$\mathrm{A}=\frac{\mathrm{V}}{\mathrm{l}}$
$\Delta \mathrm{l}=\frac{\mathrm{Fl}^{2}}{\mathrm{YV}}$