A column of length L with both ends fixed may be considered equivalent to a column of length ______ with both ends hinged.
Try it first: pick an option, then read the explanation.
Correct answer: B. L/2
Asked in SSC JE 03/03/2017 (Morning)
Detailed Explanation
The effective length of any column is precisely "the length of a pin-ended column with the same buckling load".
Why “L/2” Is Correct
Since a fixed–fixed column has le = L/2, it is equivalent to a hinged–hinged column of length L/2.
Why the Other Options Are Wrong
- A. L/8: L/8 is too short — no standard case gives it.
- C. L/4: L/4 is the distance from each end to an inflection point, not the equivalent length.
- D. L: L would mean fixing the ends adds no strength.
Key Point
Fixed–fixed column of length L ≡ hinged–hinged column of length L/2.
Key Concepts for Students
- Equivalent length = distance between inflection points.
- Same idea gives 2L for fixed–free.
- P = 4π²EI/L².
Practice more: this is question 22 in Columns and Struts MCQs – Part 2. Try the whole set and check every answer instantly.