Fluid Mechanics MCQs with Answers – KTU Exam Preparation

 

“Fluid Mechanics MCQs – Beginner to Intermediate Level”

Fluid Mechanics is a core subject in Civil and Mechanical Engineering, forming the foundation for hydraulics, pipe flow, open channel flow, and fluid machinery. 

The following MCQs are designed for KTU‑level exams and competitive tests.

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1. The density of water at 4°C is approximately:

• A) 900 kg/m³

• B) 1000 kg/m³

• C) 1200 kg/m³

• D) 1500 kg/m³

Answer: B Explanation: Water has maximum density at 4°C, around 1000 kg/m³.

2. The ratio of specific weight to density is:

• A) Pressure

• B) Kinematic viscosity

• C) Acceleration due to gravity

• D) Dynamic viscosity

Answer: C Explanation: $\gamma \mathrm{/}\rho =g$.

3. Pascal’s law applies to:

• A) Gases only

• B) Liquids only

• C) Fluids at rest

• D) Fluids in motion

Answer: C Explanation: Pascal’s law states that pressure applied to a confined fluid is transmitted equally in all directions.

4. The unit of dynamic viscosity in SI is:

• A) m²/s

• B) N·s/m²

• C) kg/m³

• D) Pa

Answer: B Explanation: Dynamic viscosity is measured in N·s/m² (or Pa·s).

5. A fluid is defined as a substance that:

• A) Cannot be compressed

• B) Offers no resistance to shear stress

• C) Deforms continuously under shear stress

• D) Has fixed shape

Answer: “Fluid Mechanics MCQs – Beginner to Intermediate Level” Explanation: Continuous deformation under shear is the defining property of fluids.

6. The pressure at a depth $h$ in a static fluid is:

• A) $\rho gh$

• B) $\rho \mathrm{/}gh$

• C) $g\mathrm{/}\rho h$

• D) $\rho g\mathrm{/}h$

Answer: A Explanation: Hydrostatic pressure increases linearly with depth.

7. The continuity equation for incompressible flow is:

• A) $Q=A+V$

• B) $Q=A\mathrm{/}V$

• C) $Q=AV$

• D) $Q=V\mathrm{/}A$

Answer: C Explanation: Discharge is area × velocity.

8. Bernoulli’s equation is applicable to:

• A) Viscous flows

• B) Compressible flows

• C) Steady, incompressible, frictionless flows

• D) Turbulent flows only

Answer: C Explanation: Bernoulli’s equation assumes ideal fluid conditions.

9. The Reynolds number is used to determine:

• A) Pressure variation

• B) Flow regime

• C) Fluid density

• D) Surface tension

Answer: B Explanation: Reynolds number classifies flow as laminar, transitional, or turbulent.

10. A manometer measures:

• A) Temperature

• B) Velocity

• C) Pressure difference

• D) Density

Answer: C Explanation: Manometers measure pressure difference using a column of liquid.