# Hydraulic Machines Questions and Answers – Centrifugal Pumps

This set of Hydraulic Machines Multiple Choice Questions & Answers (MCQs) focuses on “Centrifugal Pumps”.

1. Centrifugal pump is a_________
a) Turbomachinery
b) Flow regulating device
c) Drafting device
d) Intercooling device

Explanation: Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

2. Turbomachines work under ________
a) Newtons first law
b) Newtons second law
c) Newtons third law
d) Kepler’s law

Explanation: Turbomachines work under Newtons second law. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

3. The main function of nozzle is to __________
a) Varying temperatures
b) Pressure variations
d) Heat variations

Explanation: The main function of nozzle is to vary the pressure of fluid passing through the nozzle. It is done by opening and shutting the sets of nozzles. Thus, its main function is to regulate pressure of the fluid.

4. The main function of centrifugal pumps are to ________
a) Transfer speed
b) Transfer pressure
c) Transfer temperature
d) Transfer energy

Explanation: The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery. Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. It is a mechanical device.

5. Centrifugal pumps transfer energy from _______
a) Rotor to fluid
b) Fluid to rotor
c) Draft to rotor
d) Rotor to draft

Explanation: Centrifugal pumps transfer energy from rotor to fluid. The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery.

6. Which among the following control the flow rate?
a) Valve
b) Pump
d) Tank pipe

Explanation: Flow rate of the tank is controlled by the valve. The actuation of individual valve closes. This corresponds to the set of nozzle thereby controlling the actual flow rate of the fluid passing through the valve.

7. Turbines and compressors work with the gas, while centrifugal pump transfers energy.
a) True
b) False

Explanation: Turbines and compressors work with the gas, while centrifugal pump transfers energy. Centrifugal pumps transfer energy from rotor to fluid. The primary objective of a centrifugal pump is to transfer energy. Centrifugal pump is a turbomachinery.

8. The inlet passage of water entry is controlled by ________
b) Gate
c) Tail race
d) Pump

Explanation: The inlet passage of water entry is controlled by the gate opening. The gate opening is an opening that sends only a percentage of fluid through the inlet passages for water to enter to the turbine.

9. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery.
a) True
b) False

Explanation: The statement is true. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery. The main function of centrifugal pumps are to transfer energy.

10. Centrifugal pumps are used to transport ________
a) Pressure
b) Speed
c) Power
d) Fluid

Explanation: Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies. Centrifugal pumps are a sub class of dynamic axisymmetric work absorbing turbomachinery.

11. Centrifugal pumps transport fluids by converting _________
a) Kinetic energy to hydrodynamic energy
b) Hydrodynamic energy to kinetic energy
c) Mechanical energy to kinetic energy
d) Mechanical energy to Hydrodynamic energy

Explanation: Centrifugal pumps are used to transport fluids. They transport fluids by conversion of energies. Centrifugal pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy.

12. With the increase in load, Energy in the turbine________
a) Decreases
b) Increases
c) Remains same
d) Independent

Explanation: When there is an increase in the load, the energy in the turbine is drained off. Thus, to increase the energy, the by pass valve is opened to increase the amount of fresh steam entry. This increases the energy in the turbine.

13. The rotational kinetic energy comes from ______
a) Engine motor
b) Pump
c) Tank
d) Draft tube

Explanation: Centrifugal pumps transport fluids by converting rotational Kinetic energy to hydrodynamic energy. The rotational kinetic energy comes from engine or electrical motor.

14. When the balancing of the turbine is disturbed, we use ________
a) Throttle governing
b) Steam governing
c) Nozzle governing
d) Emergency governing

Explanation: When the balancing of the turbine is disturbed, we use emergency governing. These governors come into action only when there are emergencies in the turbine.

15. The fluid coming into the centrifugal pump is accelerated by ________
a) Throttle
b) Impeller
c) Nozzle
d) Governor

Explanation: The fluid coming into the centrifugal pump is accelerated by an impeller. The fluid enters the pump along a radially outward direction into the diffuser or a volute chamber.

Sanfoundry Global Education & Learning Series – Hydraulic Machines.

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