Fluid Machinery Set 1
Fluid Machinery — MCQ Quiz (10 Questions)
Choose one option per question. Click Show Answer to reveal the correct option (and short explanation).
1
Euler’s turbomachinery equation primarily relates which of the following?
Correct: A
Euler’s equation describes energy transfer between the rotor and the fluid (change in fluid’s angular momentum → energy/torque exchange).
Euler’s equation describes energy transfer between the rotor and the fluid (change in fluid’s angular momentum → energy/torque exchange).
2
A Pelton wheel turbine is most suitable for which condition?
Correct: B
Pelton wheels are impulse turbines best used for high head and relatively low flow applications.
Pelton wheels are impulse turbines best used for high head and relatively low flow applications.
3
What type of turbine is the Kaplan turbine?
Correct: C
Kaplan turbines are reaction machines with axial flow and adjustable blades — ideal for low head, high flow.
Kaplan turbines are reaction machines with axial flow and adjustable blades — ideal for low head, high flow.
4
Cavitation in pumps occurs when:
Correct: A
Cavitation bubbles form when local pressure drops below vapor pressure; their collapse causes damage and noise.
Cavitation bubbles form when local pressure drops below vapor pressure; their collapse causes damage and noise.
5
Specific speed (Ns) of a turbine helps to:
Correct: D
Specific speed groups turbines by shape/performance (helps choose between Pelton, Francis, Kaplan, etc. for given flow & head).
Specific speed groups turbines by shape/performance (helps choose between Pelton, Francis, Kaplan, etc. for given flow & head).
6
What is the primary purpose of specifying required NPSH (Net Positive Suction Head) for a pump?
Correct: C
Required NPSH tells you the minimum suction head needed at pump inlet to prevent cavitation.
Required NPSH tells you the minimum suction head needed at pump inlet to prevent cavitation.
7
Which of the following is a positive displacement pump?
Correct: B
Gear pumps are positive displacement machines that deliver a fixed volume per revolution (good for viscous fluids and metering).
Gear pumps are positive displacement machines that deliver a fixed volume per revolution (good for viscous fluids and metering).
8
The efficiency of a centrifugal pump is maximum near which operating point?
Correct: A
Centrifugal pumps are most efficient near their Best Efficiency Point — the design operating point.
Centrifugal pumps are most efficient near their Best Efficiency Point — the design operating point.
9
Flow through a Francis turbine is best described as:
Correct: C
Francis turbines operate with mixed flow — the flow has radial and axial components through the runner.
Francis turbines operate with mixed flow — the flow has radial and axial components through the runner.
10
What is the main function of a draft tube in a reaction turbine?
Correct: B
Draft tubes convert the kinetic energy of the exiting fluid into pressure, increasing the effective head and efficiency.
Draft tubes convert the kinetic energy of the exiting fluid into pressure, increasing the effective head and efficiency.