What is the main purpose of a centrifugal pump impeller?
A Increase pressure
B Convert mechanical energy to fluid energy
C Increase velocity
D Direct water flow
The impeller in a centrifugal pump converts the mechanical energy supplied by the motor into fluid energy by increasing the velocity of the water. This energy is then used to generate pressure for fluid movement.
What is the primary function of a jet pump?
A Increase water flow rate
B Store hydraulic energy
C Reduce water velocity
D Lift water using pressure difference
A jet pump uses a high-pressure jet of water to create a vacuum, which lifts the fluid from a lower elevation to a higher one. This is commonly used in well-pumping applications.
What is the primary advantage of using a Kaplan turbine?
A Adjustable blades for variable flow conditions
B High head, low flow capacity
C Fixed blades for efficient operation
D Low efficiency under varying conditions
The Kaplan turbine is designed with adjustable blades, allowing it to operate efficiently under varying flow conditions, particularly in low-head, high-flow environments like large hydropower plants.
In a reaction turbine, what happens to water as it passes through the turbine blades?
A Water velocity decreases, pressure increases
B Water pressure remains constant
C Water velocity increases, pressure decreases
D Water velocity and pressure both decrease
In a reaction turbine, water flows through the blades, where the pressure decreases and the velocity increases. The turbine blades extract energy from both the pressure and kinetic energy of the water.
What does a surge tank prevent in a hydraulic system?
A Sudden temperature rise
B Pressure fluctuations or water hammer
C Fluid contamination
D Excessive fluid velocity
A surge tank absorbs sudden changes in pressure caused by water hammer in hydraulic systems. This helps to maintain the stability of the system and protects pipes and equipment from potential damage.
What is the role of a hydraulic gate in a canal?
A Store water
B Generate power
C Regulate water flow and levels
D Reduce water velocity
A hydraulic gate is used in canals to control the flow and water level. It regulates the amount of water passing through the system, ensuring consistent flow for irrigation or other uses.
How does water hammer affect pipes in a hydraulic system?
A Increases water velocity
B Reduces fluid flow rate
C Maintains steady pressure
D Creates pressure surges that damage pipes
Water hammer occurs when the flow of water is suddenly stopped, causing a pressure surge that can damage pipes, valves, and other components in the hydraulic system. It is a common problem in pipelines and requires mitigation measures.
What type of energy is primarily utilized in a Pelton wheel turbine?
A Kinetic energy of water
B Thermal energy
C Gravitational energy
D Potential energy of water
The Pelton wheel turbine uses the kinetic energy of water in the form of high-velocity jets. This energy is converted into mechanical energy as the water strikes the turbine’s buckets, causing it to rotate.
What does “head loss” refer to in a hydraulic system?
A Decrease in water flow rate
B Loss of energy due to friction or turbulence
C Increase in water velocity
D Reduction in water pressure
Head loss refers to the energy lost due to friction between the fluid and the pipe walls or due to turbulence in the system. This loss results in a decrease in available pressure and flow rate.
In which type of turbine is water directed tangentially to the blades?
A Kaplan turbine
B Pelton wheel
C Francis turbine
D Reaction turbine
In a Pelton wheel turbine, water is directed tangentially to the turbine blades at high velocity. This design maximizes the conversion of the kinetic energy of water into mechanical energy.
How is cavitation prevented in hydraulic pumps?
A By reducing the fluid velocity
B By increasing pump speed
C By ensuring sufficient suction pressure
D By using larger pipes
Cavitation is prevented in hydraulic pumps by maintaining a sufficient suction pressure (NPSH). If the pressure falls too low, vapor bubbles form, leading to cavitation. Proper pump priming and system maintenance help avoid this issue.
What is the function of a velocity diagram in a turbine?
A To analyze fluid velocities and energy transfer
B To visualize flow direction
C To determine pressure variations
D To calculate power output
A velocity diagram is used to analyze the velocities of fluid entering and exiting a turbine. This helps in understanding how energy is transferred from the fluid to the turbine and optimizing its design for better performance.
What is the main advantage of using a fluid coupling in a mechanical system?
A Increase efficiency
B Reduce power consumption
C Increase turbine speed
D Smooth power transmission
A fluid coupling provides smooth power transmission by using fluid to transmit rotational energy between shafts. It helps prevent mechanical shock and reduces wear and tear in systems like pumps, turbines, and engines.
What happens during a hydraulic jump in an open channel?
A Water depth decreases
B Water velocity increases
C Water velocity decreases and depth increases
D Energy is added to the system
A hydraulic jump occurs when fast-moving water abruptly slows down, resulting in an increase in flow depth and turbulence. This energy-dissipating phenomenon is used in channels to control flow and reduce erosion.
What happens during a hydraulic jump in an open channel?
A Energy is added to the system
B Water velocity decreases and depth increases
C Water depth decreases
D Water velocity increases
A hydraulic jump occurs when fast-moving water abruptly slows down, resulting in an increase in flow depth and turbulence. This energy-dissipating phenomenon is used in channels to control flow and reduce erosion.