Question

As shown in the figure, in an experiment to determine Young's modulus of a wire. the extension-load curve is plotted. The curve is a straight line passing through the origin and makes an angle of $45^{\circ}$ with the load axis. The length of wire is $62.8 \,cm$ and its diameter is $4 \,mm$. The Young's modulus is found to be $x \times 10^4 Nm ^{-2}$. The value of $x$ is

Answer 1

From graph :
$F =\Delta L $
$ Y =\frac{ FL }{ A \Delta L }$
$Y =\frac{ L }{ A } $
$ Y =\frac{62.8 \times 10^{-2}}{\pi\left(2 \times 10^{-3}\right)^2}$
$ Y =5 \times 10^4 N / m ^2$