GATE 2022 ME (ME2) – Question 16
Which one of the following is the definition of ultimate tensile strength (UTS) obtained from a stress-strain test on a metal specimen?
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Correct answer: (B) The maximum load attained divided by the original cross-sectional area
Explanation
The stress-strain test records load $P$ against elongation. **Engineering stress** is always load divided by the **original** area $A_0$.
- **A** describes the yield point, not the UTS.
- **B:** UTS is the highest engineering stress reached, $\sigma_{UTS}=P_{max}/A_0$. ✓
- **C** divides by the instantaneous area, which gives true stress, not engineering stress.
- **D** is the fracture stress, which is usually lower than the UTS because the specimen necks and the load falls before fracture.
Answer **B**.