FLUID MECHANICS MCQ SET 7
Q1. Francis turbine is a:
A) Axial flow turbine
B) Radial flow turbine
C) Mixed flow turbine
D) Tangential flow turbine
Answer: C) Mixed flow turbine
Explanation: The Francis turbine allows fluid to enter radially and exit axially, hence called a mixed flow turbine.
Q2. Kaplan turbine is a:
A) Radial flow turbine
B) Axial flow turbine
C) Mixed flow turbine
D) Tangential flow turbine
Answer: B) Axial flow turbine
Explanation: The Kaplan turbine is an axial-flow reaction turbine, ideal for low-head, high-flow applications.
Q3. Specific speed of a turbine is defined as the speed of a geometrically similar turbine which produces:
A) Unit head and unit power
B) Unit head and unit discharge
C) Unit discharge and unit efficiency
D) Unit head only
Answer: A) Unit head and unit power
Explanation: Specific speed helps compare turbinesโ performance at unit head and power.
Q4. In dimensional analysis, Buckinghamโs ฯ theorem helps in:
A) Deriving dimensionless parameters
B) Calculating power directly
C) Reducing number of variables
D) Both A and C
Answer: D) Both A and C
Explanation: ฯ theorem simplifies experiments by grouping variables into dimensionless numbers.
Q5. The Froude number represents the ratio of:
A) Inertial force to viscous force
B) Inertial force to gravity force
C) Pressure force to viscous force
D) Elastic force to viscous force
Answer: B) Inertial force to gravity force
Q6. Mach number is the ratio of:
A) Fluid velocity to wave velocity
B) Velocity of fluid to speed of sound
C) Sound velocity to fluid velocity
D) Density ratio
Answer: B) Velocity of fluid to speed of sound
Explanation: Mach number = V/a , indicates compressibility effects in high-speed flows.
Q7. Reynolds number is important because it:
A) Predicts type of flow
B) Measures density
C) Determines pressure drop only
D) Calculates flow velocity
Answer: A) Predicts type of flow
Explanation: Reynolds number helps classify flow as laminar, transitional, or turbulent.
Q8. Weber number is used in problems involving:
A) Viscous forces
B) Surface tension forces
C) Gravity forces
D) Elastic forces
Answer: B) Surface tension forces
Explanation: Weber number = Inertia force / Surface Tension Force ; important in droplet and jet flows.
Q9. Eulerโs number represents:
A) Ratio of pressure force to inertial force
B) Ratio of gravity to viscous force
C) Ratio of kinetic to surface tension force
D) None
Answer: A) Ratio of pressure force to inertial force
Explanation: Euler number is dimensionless and used in pressure-flow analysis.
Q10. The flow of air around an aircraft wing is:
A) Compressible
B) Incompressible
C) Viscous
D) Laminar
Answer: A) Compressible
Explanation: At high speeds, air density changes significantly, making the flow compressible.
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