The equivalent length of a column of length L having both ends hinged is:
Try it first: pick an option, then read the explanation.
Correct answer: B. L
Asked in SSC JE 29/01/2018 (Evening)
Detailed Explanation
The effective (equivalent) length of any column is compared with the pin-ended column, whose buckled shape is a full half sine wave between the hinges.
Why “L” Is Correct
For both ends hinged, the equivalent length is the actual length: L.
Why the Other Options Are Wrong
- A. 2L: 2L is for one end fixed, other free.
- C. L/2: L/2 is for both ends fixed.
- D. L/√2: L/√2 is for one end fixed, other hinged.
Key Point
Hinged–hinged: le = L (the reference case).
Key Concepts for Students
- Inflection points of the buckled shape sit at the two hinges.
- P = π²EI/L².
- IS 800 also uses 1.0L.
Practice more: this is question 12 in Columns and Struts MCQs – Part 1. Try the whole set and check every answer instantly.