Physics Question on potential energy

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
In an experiment to determine Young's modulus of a wire the extension-load curve is plotted.

Accepted Answer

The correct answer is 5.
In an experiment to determine Young's modulus of a wire. the extension-load curve is plotted

From graph :
F=ΔL
Y=AΔLFL
Y=AL
Y=π(2×10−3)262.8×10−2
Y=5×104N/m2