Stress-Strain Curve, Thermal Stress and Elastic PE — NEET Physics PYQ MCQs with Solutions
Free NEET Physics PYQ Stress-Strain Curve, Thermal Stress and Elastic PE MCQs with step-by-step solutions (2 questions). Part of Mechanical Properties of Solids. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Stress-Strain Curve, Thermal Stress and Elastic PE · medium · theory
The stress-strain curves are drawn for two different materials $X$ and $Y$. It is observed that the ultimate strength point and the fracture point are close to each other for material $X$ but are far apart for material $Y$. We can say that materials $X$ and $Y$ are likely to be (respectively)
A. ductile and brittle
B. brittle and ductile ✓ Correct
C. brittle and plastic
D. plastic and ductile
Solution: If the ultimate strength point and fracture point are close, the material breaks soon after its strength limit — it is brittle ($X$). If they are far apart, the material withstands large strain before fracturing — it is ductile ($Y$).
Q2 — Stress-Strain Curve, Thermal Stress and Elastic PE · medium · numerical
When a block of mass $M$ is suspended by a long wire of length $L$, the length of the wire becomes $(L+l)$. The elastic potential energy stored in the extended wire is
A. $MgL$
B. $\dfrac{1}{2}Mgl$ ✓ Correct
C. $\dfrac{1}{2}MgL$
D. $Mgl$
Solution: Elastic PE $=\dfrac{1}{2}\times$ force $\times$ elongation $=\dfrac{1}{2}\times Mg\times l=\dfrac{1}{2}Mgl$.