Question

Consider the following salient points in a stress-strain curve of mild steel bar: (A) Yield point
(B) Breaking point
(C) Proportionality limit
(D) Ultimate point
The correct sequence in which they occur while testing the mild steel bar in tension from initial zero strain to failure is:

• A. (A), (B), (C), (D)
• B. (A), (B), (C) only
• C. (C), (A), (D), (B)
• D. (B), (C) and (D) only

Hint:

In a stress-strain curve, the yield point comes first, followed by the proportional limit, ultimate point, and finally the breaking point.

Answer 1

The Correct Option is A

Step 1: Understanding the Stress-Strain Curve.
- (A) Yield point: This is where the material first begins to deform plastically.
- (B) Breaking point: This is the point at which the material fails, or breaks.
- (C) Proportionality limit: This is the point where the stress and strain remain proportional, before yielding.
- (D) Ultimate point: This is the maximum stress the material can withstand before breaking.

Step 2: Conclusion.
The correct order of events while testing the mild steel bar is (A) Yield point, (B) Breaking point, (C) Proportionality limit, and (D) Ultimate point. Therefore, option (1) is correct.

Final Answer: \[ \boxed{1. \, (A), (B), (C), (D)} \]