The 'surface overflow rate' (SOR) in a sedimentation tank is defined as:
Choose the correct answer
Volume of tank divided by depth
Flow rate per unit plan area (m/day) — governs settling efficiency; particles settle if vs ≥ SOR
Number of settling tanks required
Sludge removal rate
Correct Answer
B. Flow rate per unit plan area (m/day) — governs settling efficiency; particles settle if vs ≥ SOR
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
SOR = Q/A (m³/m²/day or m/day) where Q = flow rate, A = plan area of tank. A particle settles completely if its terminal settling velocity vs ≥ SOR. If vs < SOR, partial removal. Stoke''s law: vs = (ρs−ρ)gd²/(18μ). Typical SOR for primary clarifier: 30–50 m³/m²/day. SOR governs plan area design (not depth).
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.