1. What is the definition of fluid in the context of fluid mechanics?
A. A substance that flows under the action of a force
B. A substance that does not have a definite shape
C. A substance that has a fixed volume
D. A substance that resists deformation
Answer: a) A substance that flows under the action of a force
Rationale: Fluids are materials that flow and have no fixed shape, only volume. This
makes them deformable when subjected to a force.
2. What is the primary difference between liquids and gases?
A. Liquids are incompressible, gases are compressible
B. Liquids have higher density than gases
C. Gases have a fixed volume, liquids do not
D. Liquids are non-flowing, gases are flowing
Answer: a) Liquids are incompressible, gases are compressible
Rationale: Liquids have a nearly constant density, while gases can be compressed and
expand significantly in response to changes in pressure or temperature.
,3. Which of the following is the SI unit for viscosity?
A. Pascal
B. Newton-second per meter squared
C. Meter per second
D. Kilogram per meter per second
Answer: b) Newton-second per meter squared
Rationale: The SI unit of dynamic viscosity is the Newton-second per meter squared,
also called the pascal-second (Pa•s).
4. In fluid mechanics, what does Bernoulli’s principle state?
A. Total energy in a fluid remains constant if the flow is steady and incompressible
B. Pressure in a fluid is directly proportional to velocity
C. The viscosity of a fluid is constant at all velocities
D. Fluid flow is always turbulent
Answer: a) Total energy in a fluid remains constant if the flow is steady and
incompressible
Rationale: Bernoulli’s principle explains how pressure and velocity are related in
steady, incompressible flow, stating that the total mechanical energy is conserved.
, 5. The Reynolds number (Re) is used to predict which type of flow?
A. Laminar flow
B. Turbulent flow
C. Steady flow
D. Compressible flow
Answer: b) Turbulent flow
Rationale: The Reynolds number helps to determine whether the flow is laminar or
turbulent. A low Reynolds number indicates laminar flow, while a high number
indicates turbulent flow.
6. The equation of continuity is based on the principle of?
A. Conservation of mass
B. Conservation of energy
C. Conservation of momentum
D. Conservation of volume
Answer: a) Conservation of mass
Rationale: The equation of continuity is based on the principle of mass conservation,
stating that the mass flow rate in a closed system is constant.
A. A substance that flows under the action of a force
B. A substance that does not have a definite shape
C. A substance that has a fixed volume
D. A substance that resists deformation
Answer: a) A substance that flows under the action of a force
Rationale: Fluids are materials that flow and have no fixed shape, only volume. This
makes them deformable when subjected to a force.
2. What is the primary difference between liquids and gases?
A. Liquids are incompressible, gases are compressible
B. Liquids have higher density than gases
C. Gases have a fixed volume, liquids do not
D. Liquids are non-flowing, gases are flowing
Answer: a) Liquids are incompressible, gases are compressible
Rationale: Liquids have a nearly constant density, while gases can be compressed and
expand significantly in response to changes in pressure or temperature.
,3. Which of the following is the SI unit for viscosity?
A. Pascal
B. Newton-second per meter squared
C. Meter per second
D. Kilogram per meter per second
Answer: b) Newton-second per meter squared
Rationale: The SI unit of dynamic viscosity is the Newton-second per meter squared,
also called the pascal-second (Pa•s).
4. In fluid mechanics, what does Bernoulli’s principle state?
A. Total energy in a fluid remains constant if the flow is steady and incompressible
B. Pressure in a fluid is directly proportional to velocity
C. The viscosity of a fluid is constant at all velocities
D. Fluid flow is always turbulent
Answer: a) Total energy in a fluid remains constant if the flow is steady and
incompressible
Rationale: Bernoulli’s principle explains how pressure and velocity are related in
steady, incompressible flow, stating that the total mechanical energy is conserved.
, 5. The Reynolds number (Re) is used to predict which type of flow?
A. Laminar flow
B. Turbulent flow
C. Steady flow
D. Compressible flow
Answer: b) Turbulent flow
Rationale: The Reynolds number helps to determine whether the flow is laminar or
turbulent. A low Reynolds number indicates laminar flow, while a high number
indicates turbulent flow.
6. The equation of continuity is based on the principle of?
A. Conservation of mass
B. Conservation of energy
C. Conservation of momentum
D. Conservation of volume
Answer: a) Conservation of mass
Rationale: The equation of continuity is based on the principle of mass conservation,
stating that the mass flow rate in a closed system is constant.
