The greatest load which a spring can carry without getting permanently distorted is called:
Try it first: pick an option, then read the explanation.
Correct answer: D. proof load
Asked in SSC JE 23/01/2018 (Evening)
Detailed Explanation
Load a spring beyond a certain point and it does not return to its original length. The largest load short of that is its proof load.
Why “proof load” Is Correct
It is called the proof load; the corresponding wire stress is the proof stress.
| Term | Meaning |
|---|---|
| Stiffness k | Load per unit deflection, k = W/δ |
| Proof load | Greatest load the spring can carry without permanent distortion |
| Proof stress | Maximum stress in the wire at the proof load |
| Proof resilience | Strain energy stored at the proof load, U = ½Wδ |
Why the Other Options Are Wrong
- A. stiffness: Stiffness is load per unit deflection.
- B. proof resilience: Proof resilience is the energy stored at the proof load.
- C. proof stress: Proof stress is the stress at the proof load, not the load.
Key Point
Proof load → proof stress (stress at it) → proof resilience (energy at it).
Key Concepts for Students
- Springs are tested to the proof load.
- Working load is kept below the proof load.
- Beyond it the spring takes a permanent set.
Practice more: this is question 10 in Spring MCQs – Part 1. Try the whole set and check every answer instantly.