The 'model law' for open channel hydraulic models is based on equality of:
Choose the correct answer
Reynolds number between model and prototype
Froude number between model and prototype — gravity dominates free-surface flow
Weber number only (surface tension)
Mach number (compressibility)
Correct Answer
B. Froude number between model and prototype — gravity dominates free-surface flow
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
Open channel (free surface flow): governed by gravity → Froude number similarity law (Froude''s model law). Fr_model = Fr_prototype: Vm/√(gLm) = Vp/√(gLp). For undistorted model with geometric scale Lr: Vr = Lr^(1/2), Qr = Lr^(5/2), tr = Lr^(1/2). Pipe flow models (pressure flow, no free surface): Reynolds number law applies.
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.