FLUID MECHANICS: FUNDAMENTALS
AND APPLICATIONS COMPREHENSIVE
EXAM QUESTIONS AND ANSWERS
1. Which of the following describes the no-slip condition in fluid mechanics?
A. The pressure at the boundary must be equal to the atmospheric pressure.
B. The fluid velocity at the center of the pipe is zero due to friction.
C. The fluid velocity at the solid boundary is equal to the velocity of the boundary.
D. The shear stress at the solid boundary is always zero.
Answer: C
Conceptual Explanation: The no-slip condition states that a fluid in direct contact with a
solid surface ‘sticks’ to the surface due to viscous effects, meaning its velocity matches the
surface velocity.
2. How does the dynamic viscosity of a typical liquid change with increasing temperature?
A. It increases significantly.
B. It decreases.
C. It remains constant regardless of temperature.
,D. It first increases and then decreases.
Answer: B
Conceptual Explanation: In liquids, viscosity is primarily caused by cohesive forces
between molecules. As temperature increases, these forces weaken, leading to a decrease
in viscosity.
3. Cavitation in a fluid system occurs when:
A. The local pressure falls below the vapor pressure of the liquid.
B. The fluid temperature drops below the freezing point.
C. The local pressure exceeds the stagnation pressure.
D. The velocity of the fluid reaches the speed of sound.
Answer: A
Conceptual Explanation: Cavitation is the formation of vapor bubbles in a liquid when the
local pressure drops below the vapor pressure, followed by the sudden collapse of these
bubbles when they move to higher pressure regions.
4. The Bulk Modulus of Elasticity is a measure of a fluid’s:
A. Resistance to shear deformation.
B. Ability to conduct heat.
C. Compressibility or resistance to volume change.
D. Surface tension intensity.
, Answer: C
Conceptual Explanation: The Bulk Modulus represents the change in pressure required to
achieve a fractional change in volume; a higher value indicates a less compressible fluid.
5. In a static fluid, the pressure at a point is the same in all directions. This is known as:
A. Newton’s Second Law.
B. Bernoulli’s Principle.
C. Archimedes’ Principle.
D. Pascal’s Law.
Answer: D
Conceptual Explanation: Pascal’s Law states that pressure applied to a confined fluid is
transmitted undiminished to every portion of the fluid and to the walls of the container.
6. For a floating body to be in a stable equilibrium, where must the metacenter (M) be
located relative to the center of gravity (G)?
A. Below the center of gravity.
B. Above the center of gravity.
C. At the same point as the center of gravity.
D. At the center of buoyancy.
Answer: B
AND APPLICATIONS COMPREHENSIVE
EXAM QUESTIONS AND ANSWERS
1. Which of the following describes the no-slip condition in fluid mechanics?
A. The pressure at the boundary must be equal to the atmospheric pressure.
B. The fluid velocity at the center of the pipe is zero due to friction.
C. The fluid velocity at the solid boundary is equal to the velocity of the boundary.
D. The shear stress at the solid boundary is always zero.
Answer: C
Conceptual Explanation: The no-slip condition states that a fluid in direct contact with a
solid surface ‘sticks’ to the surface due to viscous effects, meaning its velocity matches the
surface velocity.
2. How does the dynamic viscosity of a typical liquid change with increasing temperature?
A. It increases significantly.
B. It decreases.
C. It remains constant regardless of temperature.
,D. It first increases and then decreases.
Answer: B
Conceptual Explanation: In liquids, viscosity is primarily caused by cohesive forces
between molecules. As temperature increases, these forces weaken, leading to a decrease
in viscosity.
3. Cavitation in a fluid system occurs when:
A. The local pressure falls below the vapor pressure of the liquid.
B. The fluid temperature drops below the freezing point.
C. The local pressure exceeds the stagnation pressure.
D. The velocity of the fluid reaches the speed of sound.
Answer: A
Conceptual Explanation: Cavitation is the formation of vapor bubbles in a liquid when the
local pressure drops below the vapor pressure, followed by the sudden collapse of these
bubbles when they move to higher pressure regions.
4. The Bulk Modulus of Elasticity is a measure of a fluid’s:
A. Resistance to shear deformation.
B. Ability to conduct heat.
C. Compressibility or resistance to volume change.
D. Surface tension intensity.
, Answer: C
Conceptual Explanation: The Bulk Modulus represents the change in pressure required to
achieve a fractional change in volume; a higher value indicates a less compressible fluid.
5. In a static fluid, the pressure at a point is the same in all directions. This is known as:
A. Newton’s Second Law.
B. Bernoulli’s Principle.
C. Archimedes’ Principle.
D. Pascal’s Law.
Answer: D
Conceptual Explanation: Pascal’s Law states that pressure applied to a confined fluid is
transmitted undiminished to every portion of the fluid and to the walls of the container.
6. For a floating body to be in a stable equilibrium, where must the metacenter (M) be
located relative to the center of gravity (G)?
A. Below the center of gravity.
B. Above the center of gravity.
C. At the same point as the center of gravity.
D. At the center of buoyancy.
Answer: B
