Sarda falls crest comparison: For identical head and geometric parameters, the ratio of discharge over a trapezoidal crest to that over a rectangular crest (Sarda type) is approximately:

Introduction / Context:Sarda fall crests are standardized profiles used in canal drops. The discharge coefficient varies slightly with crest geometry; trapezoidal crests generally pass a bit more discharge than rectangular crests under the same head and width conditions.

Given Data / Assumptions:

• Identical head, approach conditions, and overall width; only crest shape differs.
• Ratio sought: Q_trapezoidal / Q_rectangular.

Concept / Approach:Empirical calibration of Sarda crest shapes shows small but consistent increments for trapezoidal sections due to improved flow contraction and velocity distribution, leading to a discharge ratio modestly above unity, typically quoted near 1.07.

Step-by-Step Solution:Recognize that the trapezoidal crest has a slightly higher effective coefficient.Select the tabulated ratio closest to 1.07.Choose 1.074.

Verification / Alternative check:Design manuals list ratios around 1.07 for comparable Sarda geometries; the exact value may vary slightly with side slopes and approach conditions, but 1.074 is a standard choice for objective questions.

Why Other Options Are Wrong:

• 1.084/1.064/1.054: Reasonable but less commonly cited; 1.074 aligns with standard references.
• 2.053: Unrealistically large.

Common Pitfalls:Assuming a large difference between crest types; in reality, differences are within a few percent.

Final Answer:1.074