Proof resilience is the maximum strain energy stored in a body up to the:
Try it first: pick an option, then read the explanation.
Correct answer: B. elastic limit
Asked in SSC JE 2004
Detailed Explanation
The book places this strain-energy question in the columns chapter. Resilience is the energy a body stores and gives back on unloading.
\[ U_{proof} = \frac{\sigma_e^2}{2E}\,V \qquad \text{modulus of resilience} = \frac{\sigma_e^2}{2E} \]
Why “elastic limit” Is Correct
The maximum such energy is stored when the body is stressed to its elastic limit; beyond it, some energy is lost in permanent deformation.
Why the Other Options Are Wrong
- A. limit of proportionality: The limit of proportionality is slightly below the elastic limit; proof resilience is defined at the elastic limit.
- C. plastic limit: Beyond the elastic range energy is not fully recovered.
- D. none of these: Option (b) is correct.
Key Point
Proof resilience = σe²V/2E; per unit volume = modulus of resilience.
Key Concepts for Students
- Toughness = energy up to fracture.
- Suddenly applied load gives twice the gradual stress.
- Resilience matters for springs and impact loads.
Practice more: this is question 39 in Columns and Struts MCQs – Part 3. Try the whole set and check every answer instantly.