The 'effective length factor' k for a column in a multi-storey unbraced frame is typically:
Choose the correct answer
k < 1.0 (safer than pinned-pinned)
k > 1.0 — sway permitted means effective length exceeds column height (determined from nomograph based on joint stiffness)
k = 1.0 always
k = 0.5 (same as fixed-fixed braced)
Correct Answer
B. k > 1.0 — sway permitted means effective length exceeds column height (determined from nomograph based on joint stiffness)
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
Unbraced (sway) frames: k > 1.0 always (because column deflects in S-shape or C-shape). From nomographs (IS 800 Fig. 27-b): k depends on GA and GB (relative stiffness of beams to columns at top and bottom joints). For pinned base + fixed top: k = 2.0. For fixed both: k = 1.2 minimum. Unbraced = lateral sway permitted → more critical than braced (k < 1.0).
ScoreCardAI links this solution with subject, topic and difficulty signals so your scorecard can identify weak areas after a full mock test.
Practice more Civil Engineering questions
This MCQ belongs to JE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.