Question

The stress-strain graph for a metal wire is as shown in the figure. In the graph, the region in which Hooke’s law is obeyed, the ultimate strength and fracture points are represented by

• A. $OA$, $C$, $D$
• B. $OB$, $D$, $E$
• C. $OA$, $D$, $E$
• D. $OB$, $C$, $D$

Answer 1

Answer: (C)

In the region $OA$, the graph is linear showing that stress is proportional to the strain. Thus, in this region Hooke’s law is obeyed.

The point $D$ on the graph is known as ultimate tensile strength.
The point $E$ on the graph is known as fracture point.