EIT Fluid Mechanics 3

Question 1

What does a Moody diagram show?

Accepted Answer

Friction factor as a function of Reynolds number and relative roughness

Answer

The Moody diagram plots the Darcy friction factor against Reynolds number for various pipe roughness values.

Question 2

For a venturi meter, flow velocity is highest at:

Accepted Answer

The throat (narrowest section)

Answer

By the continuity equation, velocity is highest where the cross-sectional area is smallest — the throat.

Question 3

The kinematic viscosity ν is defined as:

Accepted Answer

μ / ρ

Answer

Kinematic viscosity ν = μ/ρ is the ratio of dynamic viscosity to fluid density, with units of m²/s.

Question 4

What does the Euler number represent in fluid mechanics?

Accepted Answer

Ratio of pressure forces to inertial forces

Answer

The Euler number Eu = ΔP/(ρv²) represents the ratio of pressure forces to inertial forces.

Question 5

Which phenomenon occurs when local static pressure in a liquid drops below vapor pressure?

Accepted Answer

Cavitation

Answer

Cavitation occurs when local pressure falls below vapor pressure, causing vapor bubbles to form and collapse.

EIT - Engineering in Training Practice Test