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 $628 \,cm$ 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

Correct Answer: 5

The correct answer is 5.

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