Pumps are devices used primarily to move liquids or gases by mechanical action. They convert mechanical energy into fluid energy to transport fluid through pipes, channels, or other systems.
What does a centrifugal pump use to move fluids?
A Centrifugal force
B Kinetic energy
C Gravity
D Hydraulic pressure
A centrifugal pump uses centrifugal force, generated by a rotating impeller, to push fluid outwards from the center of the pump, causing fluid to flow through the system.
Which of the following turbines is best suited for high-head, low-flow applications?
A Kaplan turbine
B Francis turbine
C Turgo turbine
D Pelton wheel
The Pelton wheel turbine is designed for high-head, low-flow conditions. It uses a jet of water to strike buckets attached to a wheel, converting the water’s potential energy into mechanical energy efficiently in such conditions.
What type of turbine is most commonly used in hydroelectric power plants?
A Kaplan turbine
B Pelton wheel
C Francis turbine
D Impulse turbine
The Francis turbine is the most commonly used turbine in hydroelectric power plants due to its versatility in handling a wide range of water flows and heads. It combines both impulse and reaction principles for optimal performance.
What is a “hydraulic jump”?
A A sudden decrease in water velocity
B A sudden drop in water pressure
C A rapid increase in water velocity
D A sudden increase in water pressure
A hydraulic jump occurs when the velocity of flowing water decreases abruptly, leading to an increase in water height and turbulence. This typically happens when high-speed water flows into a region of slower-moving water, dissipating energy.
What is the main purpose of a surge tank in a hydraulic system?
A To control turbine speed
B To regulate pressure
C To measure flow
D To store water
Surge tanks are used in hydraulic systems to absorb sudden changes in pressure, such as water hammer, and prevent damage to pipes and machinery. They help maintain the pressure at a consistent level throughout the system.
What does the term “cavitation” refer to in a hydraulic system?
A Air bubbles forming in the fluid
B Sudden temperature rise
C Excessive water flow
D High pressure in the system
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 damage to pump impellers and other components.
In a reaction turbine, the water flow direction is:
A Vertical
B Radial
C Axial
D Tangential
In a reaction turbine, water flows axially through the turbine, meaning it moves along the axis of rotation. This type of turbine uses the pressure drop and the velocity of water to generate mechanical energy.
What is the term for the loss of energy in a pipe due to friction?
A Velocity loss
B Head loss
C Pressure loss
D Turbulence loss
Head loss refers to the loss of energy due to friction as water flows through a pipe. This loss reduces the pressure and velocity of the fluid, which can impact system efficiency and performance.
What is the purpose of a spillway in a dam?
A To release excess water
B To generate power
C To filter water
D To regulate flow into turbines
A spillway is designed to safely release excess water from a reservoir to prevent overflow and potential damage to the dam. It helps control the water level, especially during heavy rainfall or snowmelt.
What is the main function of a hydraulic gate?
A To store water
B To increase water speed
C To measure flow rate
D To regulate water levels
Hydraulic gates are used to control the flow of water, either by regulating its level or by completely closing off passages. They are essential for managing water resources in dams, canals, and reservoirs.
Which of the following is a primary cause of water hammer in pipes?
A Sudden closure of a valve
B Excessive pressure
C Low fluid velocity
D High fluid temperature
Water hammer occurs when a valve is suddenly closed, causing the water flow to abruptly stop. This creates a pressure surge in the system, which can damage pipes and other components due to the rapid increase in pressure.
Which of the following is true about jet propulsion in hydraulic systems?
A It is based on static fluid pressure
B It involves the conversion of chemical energy
C It uses high-velocity fluid to generate thrust
D It is used only in turbines
Jet propulsion involves using high-velocity fluid to create thrust or motion, as seen in devices like jet engines or water‐based propulsion systems. This principle is utilized to propel objects like boats and submarines.
What is the specific speed of a pump or turbine?
A The speed at which the fluid moves through the system
B A dimensionless number that describes performance characteristics
C A measure of the pump’s efficiency
D The speed at which the turbine rotates
Specific speed is a dimensionless number used to describe the geometry and operating conditions of pumps and turbines. It helps in selecting the right type of pump or turbine based on flow rate, head, and rotational speed.
What is the role of flow measurement in hydraulic systems?
A To measure the amount of fluid passing through a section
B To monitor the efficiency of the system
C To determine water pressure
D To estimate power generation
Flow measurement is crucial for monitoring and controlling the amount of fluid passing through a hydraulic system. Accurate flow data helps in optimizing system performance, ensuring efficient energy use, and preventing system damage.