BCE Hydraulics & Fluid Mechanics

Question 1

What does Bernoulli's equation primarily conserve in fluid flow?

Accepted Answer

Energy

Answer

Bernoulli's equation is a statement of the conservation of energy along a streamline in steady, incompressible, frictionless flow.

Question 2

Which dimensionless number represents the ratio of inertial forces to viscous forces in fluid flow?

Accepted Answer

Reynolds number

Answer

The Reynolds number (Re = ρVD/μ) represents the ratio of inertial to viscous forces and determines whether flow is laminar or turbulent.

Question 3

What is the hydraulic radius of a circular pipe flowing full with diameter D?

Accepted Answer

D/4

Answer

For a full circular pipe, hydraulic radius R = Area/Wetted Perimeter = (πD²/4)/(πD) = D/4.

Question 4

Manning's equation is primarily used to calculate flow in which type of system?

Accepted Answer

Open channel flow

Answer

Manning's equation (V = (1/n)R^(2/3)S^(1/2)) is used to compute velocity and discharge in open channel flow.

Question 5

Which type of flow occurs when the Froude number is less than 1 in an open channel?

Accepted Answer

Subcritical flow

Answer

When Fr < 1, the flow is subcritical (tranquil), meaning gravitational forces dominate over inertial forces.

BCE - Bachelor of Civil Engineering Practice Test