The strain-stress plot for materials A,B,C and D is shown in the figure. Which material has the largest Young's modulus ?

Question

G1 Physics · Accepted Answer

The graph has strain on the vertical axis and stress on the horizontal axis. Young's modulus is Y = stress/strain. Therefore, strain/stress = 1/Y. Thus, on a strain-versus-stress graph, slope = 1/Y. The material with the smallest slope has the largest Young's modulus. From the plotted lines, material C has the smallest slope. Therefore material C has the largest Young's modulus. Correct option: A.