Fluid Mechanics Final Exam (FLUIDS)
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1. A fluid is defined as a substance that:
A. Has a fixed shape and volume
B. Resists deformation under shear stress
C. Continuously deforms under applied shear stress
D. Has no mass
Correct Answer: C ✓
Rationale: A fluid is characterized by its ability to continuously deform when
subjected to any amount of shear stress, unlike solids which resist deformation.
2. The SI unit of dynamic viscosity is:
A. kg/m·s
B. Pa·s
C. Both A and B
D. N/m²
Correct Answer: C ✓
Rationale: Dynamic viscosity can be expressed as Pa·s or equivalently kg/m·s,
both representing resistance to flow.
3. Which property measures resistance to flow?
A. Density
B. Viscosity
, C. Pressure
D. Temperature
Correct Answer: B ✓
Rationale: Viscosity quantifies internal friction in a fluid and determines its
resistance to flow.
4. The continuity equation is based on:
A. Energy conservation
B. Mass conservation
C. Momentum conservation
D. Heat transfer
Correct Answer: B ✓
Rationale: The continuity equation ensures mass conservation in fluid flow
systems.
5. For incompressible flow, density is:
A. Variable
B. Zero
C. Constant
D. Infinite
Correct Answer: C ✓
Rationale: In incompressible flow, fluid density remains constant regardless of
pressure changes.
6. Bernoulli’s equation applies to:
A. Viscous, compressible flow
B. Inviscid, incompressible flow
C. Turbulent only
D. Heat transfer systems only
Correct Answer: B ✓
Rationale: Bernoulli’s equation assumes inviscid (no viscosity) and
incompressible flow along a streamline.
, 7. The Reynolds number indicates:
A. Pressure level
B. Flow regime
C. Temperature gradient
D. Fluid density
Correct Answer: B ✓
Rationale: The Reynolds number predicts whether flow is laminar, transitional,
or turbulent.
8. Laminar flow is characterized by:
A. Random mixing
B. Smooth layered motion
C. High turbulence
D. Shock waves
Correct Answer: B ✓
Rationale: Laminar flow occurs in smooth, parallel layers with minimal mixing.
9. Turbulent flow generally occurs at Reynolds number:
A. < 2000
B. 2000–4000
C. > 4000
D. = 0
Correct Answer: C ✓
Rationale: Flow is typically turbulent when Re > 4000, indicating chaotic motion.
10.Pressure is defined as:
A. Force × area
B. Force per unit area
C. Mass per unit volume
D. Energy per unit mass
Newest 2026-2027 Updated Practice
Exam | 100 Most Tested Questions &
Verified Detailed Answers | Tutor
Verified Success Bundle
1. A fluid is defined as a substance that:
A. Has a fixed shape and volume
B. Resists deformation under shear stress
C. Continuously deforms under applied shear stress
D. Has no mass
Correct Answer: C ✓
Rationale: A fluid is characterized by its ability to continuously deform when
subjected to any amount of shear stress, unlike solids which resist deformation.
2. The SI unit of dynamic viscosity is:
A. kg/m·s
B. Pa·s
C. Both A and B
D. N/m²
Correct Answer: C ✓
Rationale: Dynamic viscosity can be expressed as Pa·s or equivalently kg/m·s,
both representing resistance to flow.
3. Which property measures resistance to flow?
A. Density
B. Viscosity
, C. Pressure
D. Temperature
Correct Answer: B ✓
Rationale: Viscosity quantifies internal friction in a fluid and determines its
resistance to flow.
4. The continuity equation is based on:
A. Energy conservation
B. Mass conservation
C. Momentum conservation
D. Heat transfer
Correct Answer: B ✓
Rationale: The continuity equation ensures mass conservation in fluid flow
systems.
5. For incompressible flow, density is:
A. Variable
B. Zero
C. Constant
D. Infinite
Correct Answer: C ✓
Rationale: In incompressible flow, fluid density remains constant regardless of
pressure changes.
6. Bernoulli’s equation applies to:
A. Viscous, compressible flow
B. Inviscid, incompressible flow
C. Turbulent only
D. Heat transfer systems only
Correct Answer: B ✓
Rationale: Bernoulli’s equation assumes inviscid (no viscosity) and
incompressible flow along a streamline.
, 7. The Reynolds number indicates:
A. Pressure level
B. Flow regime
C. Temperature gradient
D. Fluid density
Correct Answer: B ✓
Rationale: The Reynolds number predicts whether flow is laminar, transitional,
or turbulent.
8. Laminar flow is characterized by:
A. Random mixing
B. Smooth layered motion
C. High turbulence
D. Shock waves
Correct Answer: B ✓
Rationale: Laminar flow occurs in smooth, parallel layers with minimal mixing.
9. Turbulent flow generally occurs at Reynolds number:
A. < 2000
B. 2000–4000
C. > 4000
D. = 0
Correct Answer: C ✓
Rationale: Flow is typically turbulent when Re > 4000, indicating chaotic motion.
10.Pressure is defined as:
A. Force × area
B. Force per unit area
C. Mass per unit volume
D. Energy per unit mass
