What is the primary principle of a centrifugal pump?
A Heat transfer
B Gravitational force
C Bernoulli’s principle
D Centrifugal force
A centrifugal pump works by converting mechanical energy into kinetic energy through the rotation of an impeller. The centrifugal force generated by the impeller pushes the fluid outward, creating flow.
Which of the following turbines is typically used in low-head, high-flow applications?
A Pelton wheel
B Kaplan turbine
C Turgo turbine
D Francis turbine
The Kaplan turbine is designed for low-head, high-flow conditions. Its adjustable blades allow for efficient energy conversion even in varying water flow conditions, making it ideal for large-scale hydropower plants.
What is the main purpose of a hydraulic accumulator?
A To store potential energy
B To regulate flow
C To store electrical energy
D To increase pressure
A hydraulic accumulator is used to store energy in the form of pressurized fluid. This stored energy can be released when needed, providing a constant energy source and helping to maintain pressure in hydraulic systems.
What is the efficiency of a turbine primarily determined by?
A Speed of the water
B Water temperature
C Head and flow rate
D Pipe diameter
The efficiency of a turbine depends on the head (height of water) and flow rate (volume of water passing through). Proper matching of these factors ensures maximum energy conversion from the water to mechanical energy.
In which of the following does energy dissipation occur in a hydraulic system?
A Turbine operation
B Hydraulic jump
C Pump priming
D Velocity increase
Energy dissipation occurs during a hydraulic jump, where fast-moving water abruptly slows down. This causes turbulence and increases water height, dissipating energy in the process.
Which of the following is the most common type of cavitation?
A Vapor cavitation
B Gas cavitation
C Solid cavitation
D Vapor cavitation
Vapor cavitation occurs when the pressure in a liquid drops below its vapor pressure, causing the formation of vapor bubbles. When these bubbles collapse, they can cause severe damage to pumps and turbines.
What does the term “head” refer to in hydraulics?
A Energy potential of water
B Height of the water
C Water pressure
D Fluid velocity
“Head” refers to the height of water above a reference point and represents the potential energy of the water in a system. It is used to calculate the energy available to drive turbines or pumps.
What is the primary purpose of an impulse turbine like the Pelton wheel?
A To store energy
B To regulate water flow
C To use water velocity to generate power
D To increase turbine efficiency
Impulse turbines like the Pelton wheel convert the kinetic energy of high-velocity water jets into mechanical energy. Water strikes the turbine blades, causing them to rotate, producing power.
What type of turbine is used to harness energy from water with both high head and low flow?
A Francis turbine
B Pelton wheel
C Kaplan turbine
D Turgo turbine
The Pelton wheel is ideal for high-head, low-flow conditions. It works by using a high-speed jet of water to strike spoon-shaped buckets on the wheel, converting water’s kinetic energy into mechanical energy efficiently.
What does a surge tank protect against in a hydraulic system?
A Excessive pressure changes
B Low water levels
C Fluid contamination
D Decreased water flow
Surge tanks are used to absorb pressure surges or fluctuations in the hydraulic system. They act as a buffer, reducing the risk of damage from sudden pressure changes, such as water hammer.
Which of the following is a key feature of a Kaplan turbine?
A High-speed rotation
B Axial flow with adjustable blades
C Radial flow
D Impulse action
The Kaplan turbine features axial flow, where water flows along the axis of the turbine. Its adjustable blades allow it to efficiently handle a wide range of water flow rates, making it ideal for low-head conditions.
Which type of energy is typically associated with a hydraulic power system?
A Hydraulic energy
B Mechanical energy
C Thermal energy
D Electrical energy
Hydraulic power systems primarily use hydraulic energy, which is the energy stored in pressurized fluids. This energy can be used for tasks such as lifting, driving machinery, and operating hydraulic circuits.
What is “pump priming” in a hydraulic system?
A Starting the pump motor
B Increasing pump efficiency
C Filling the pump with liquid before starting
D Increasing fluid velocity
Pump priming involves filling the pump casing with liquid before it starts operating. This step is necessary for pumps to function properly, as air in the system can prevent the pump from creating the required suction.
In fluid mechanics, what is “velocity diagram” used for?
A To analyze velocity changes in turbines
B To show fluid pressure variations
C To measure fluid density
D To calculate flow rate
The velocity diagram is used to visualize and calculate the velocities of the fluid entering and exiting a turbine. It helps in analyzing energy transfer within the turbine and optimizing its design for efficiency.
What does a flow control system do in a hydraulic network?
A Maintains a constant flow rate
B Controls the direction of flow
C Measures water speed
D Regulates water temperature
Flow control systems are used to regulate and maintain a constant flow rate in a hydraulic network. They ensure that the system operates efficiently, preventing issues like overpressure or underflow that could cause system failures.