Q.3:- The stress-strain graphs for materials A and B are shown in Fig. 9.12.
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?
(a) From the two graphs we note that for a given strain, stress for A is more than that of B. Hence, Young’s modulus (=stress/strain) is greater for A than that of B.
(b) A is stronger than B. Strength of a material is measured by the amount of stress required to cause fracture, corresponding to the point of fracture.