ETC ETC Hydraulics & Fluid Mechanics 2

Question 1

The Reynolds number is used in fluid mechanics to determine whether flow is:

Accepted Answer

Laminar or turbulent

Answer

The Reynolds number (Re = ρVD/μ) distinguishes laminar flow (Re < 2,300) from turbulent flow (Re > 4,000) in circular pipe systems.

Question 2

A Venturi meter measures which hydraulic quantity?

Accepted Answer

Flow rate by measuring a pressure differential at a constriction

Answer

A Venturi meter calculates volumetric flow rate by measuring the pressure drop between the inlet and the narrow throat section, then applying Bernoulli's equation.

Question 3

The Darcy-Weisbach equation (hf = f × L/D × V²/2g) is used to calculate:

Accepted Answer

Head loss due to pipe wall friction

Answer

The Darcy-Weisbach equation calculates major (friction) head loss in a pipe, requiring the Darcy friction factor f, pipe length L, diameter D, and flow velocity V.

Question 4

The Hydraulic Grade Line (HGL) in a pipe system represents the sum of:

Accepted Answer

Pressure head and elevation head

Answer

The HGL equals the sum of pressure head (P/γ) and elevation head (z) at each cross-section, and represents the height to which water would rise in a piezometer.

Question 5

A manometer is an instrument primarily used to measure:

Accepted Answer

Pressure or differential pressure between two points

Answer

A manometer measures pressure or pressure differences by observing the height difference of a fluid column (commonly water or mercury) in a U-tube.

(ETC) Engineering Technician Certification Practice Test

(ETC) Engineering Technician Certification Practice Test

ETC ETC Hydraulics & Fluid Mechanics 2