Question

The stress-strain graphs for materials A and B are shown in Fig.
The graphs are drawn to the same scale.
(a) Which of the materials has the greater Young's modulus ?
(b) Which of the two is the stronger material ?

Answer 1

From Hooke's law, young's modulus $Y=\frac{Stress}{Strain}$

Thus slope of Stress Vs Strain graph gives the value of Young's modulus of a material.

From the two graphs, we see that slope for material A is greater than for B. Thus material A has greater Young's modulus.

Also, Young's modulus is the measure of strength of the material. Greater the Young's modulus, greater is the force required to produce strain in it. Hence material A is stronger than material B.