Open Channel Flow MCQ with answer and solution

Concept

Uniform vs. Non-Uniform Flow

Formula

Manning's Equation: V = (1/n) × R^2/3 × S^1/2 Chezy's Formula: V = C × √(R × S) Gradually Varied Flow Equation: dy/dx = (S0 - Sf) / (1 - Fr²)

Step-by-step solution

1. Recall that in uniform flow, velocity, depth, and cross-sectional area remain constant along the channel. 2. Match this definition with Option B, which states that uniform flow has a constant velocity across sections.

Explanation

In open channel flow, uniform flow occurs when hydraulic parameters such as flow depth, cross-sectional area, and velocity remain constant along the length of the channel. This means the flow velocity does not change from one section to another. In non-uniform flow, velocity and depth vary along the channel length.

Shortcut

Remember "Uniform = Same": in uniform flow, velocity and depth stay the same (constant) along the channel, while in non-uniform flow they change.

Common mistake

Students often confuse uniform flow (where flow velocity remains constant along the channel distance) with steady flow (where flow parameters remain constant over time), leading them to select incorrect definitions or think uniform flow only applies to closed conduits like pipes.