Question Bank • QB_SWCE_EXP_008 NAT • 1 Mark

Section 4: Soil and Water Conservation Engineering

Fluid Mechanics

Subtopic: Laminar and turbulent flow in pipes, Darcy–Weisbach and Hazen–Williams equations

Question Statement:

Water discharges from a sharp-crested circular orifice under a constant head of $4.0\text{ m}$. If the coefficient of velocity $C_v = 0.97$, the actual velocity of the jet at the vena contracta in $\text{m/s}$ is ________ (round off to 2 decimal places). Take $g = 9.81\text{ m/s}^2$.

Answer Key:

8.59

Step-by-Step Solution & Explanation

1. Theoretical velocity $V_{th} = \sqrt{2 g H}$: $V_{th} = \sqrt{2 \times 9.81 \times 4.0} = \sqrt{78.48} \approx 8.8589\text{ m/s}$ 2. Actual velocity $V_{act} = C_v \times V_{th}$: $V_{act} = 0.97 \times 8.8589 \approx 8.593\text{ m/s} \approx 8.59\text{ m/s}$
← Previous (QB_SWCE_ADV_096) Next (QB_SUB_SWCE_0115) →

Practice In Authentic CBT Exam Interface

Test your skills under authentic timed conditions with live scoring and AIR percentile ranking.

Launch CBT Mock Test