Specific speed is a dimensionless number that helps in selecting the correct turbine for a given flow rate and head. It provides insight into the turbine’s design and performance in specific operational conditions.
What is the primary function of jet propulsion?
A To generate thrust through fluid expansion
B To use high-speed jets of water or air to move an object
C To store energy
D To regulate fluid flow rate
Jet propulsion works by expelling high-velocity water or air through a nozzle, creating thrust that propels an object, such as in jet engines or watercraft, based on Newton’s third law of motion.
What does pump priming involve?
A Removing air from the pump
B Increasing pump efficiency
C Increasing water flow
D Measuring water temperature
Pump priming is the process of filling the pump with liquid before it starts operating to remove any air. This is essential for creating the necessary suction to ensure the pump functions properly.
What is the purpose of governing in turbines?
A To regulate flow direction
B To adjust water pressure
C To control turbine speed
D To prevent cavitation
Governing in turbines refers to controlling the water flow into the turbine to maintain a constant rotational speed. This ensures consistent power generation, especially when the flow rate of water changes.
What does a velocity diagram in a turbine represent?
A Fluid density changes
B The change in water velocity through the turbine
C Direction of water flow
D Pressure distribution across the turbine blades
A velocity diagram is used to analyze the changes in water velocity as it enters and exits the turbine. It helps engineers understand how efficiently the turbine converts fluid energy into mechanical energy.
What is typically used to measure the flow rate of water in a pipe?
A Pressure gauge
B Speedometer
C Flow meter
D Thermometer
A flow meter is a device used to measure the rate at which water or fluid flows through a pipe. It is essential for ensuring the correct operation of hydraulic systems and monitoring fluid usage.
What happens in a centrifugal pump when it reaches its shutoff head?
A It increases efficiency
B It stops pumping
C It starts cavitating
D It reaches maximum flow rate
In a centrifugal pump, the shutoff head is the maximum head the pump can generate at zero flow. Beyond this point, the pump will stop pumping, and fluid flow will be halted due to excessive pressure buildup.
How is energy dissipated in a hydraulic jump?
A By reducing water temperature
B By increasing the water depth and turbulence
C By storing potential energy
D By increasing the flow velocity
A hydraulic jump occurs when high-velocity water suddenly slows down, increasing water depth and causing turbulence. This dissipates energy, reducing flow velocity and increasing the flow depth.
What is the function of a fluid coupling in a hydraulic system?
A Smooth transmission of power
B Increase pressure
C Measure fluid velocity
D Store fluid energy
A fluid coupling transmits power between two rotating shafts using fluid. It provides smooth acceleration and deceleration, reducing mechanical shock, and is often used in hydraulic drives and machinery.
Which of the following best describes canal hydraulics?
A Energy generation through canals
B Pressure measurement in canals
C The regulation of water velocity in reservoirs
D The study of water flow in open channels
Canal hydraulics involves studying the behavior of water flow through open channels, such as canals, rivers, and streams. It deals with flow rate, depth, velocity, and energy dissipation in these systems.
What is the primary use of a surge tank in hydroelectric plants?
A Store water for future use
B Increase water flow
C Absorb pressure variations
D Regulate temperature
Surge tanks are used in hydroelectric power plants to absorb pressure fluctuations caused by rapid changes in water flow, such as valve closures. This prevents damage to pipes and equipment from pressure surges.
In a Francis turbine, water flows:
A Radially inward
B Axially
C Radially outward
D Tangentially
In a Francis turbine, water flows radially inward through the runner, and the energy from the water is converted into mechanical energy as it moves through the turbine blades. It is widely used in medium-head applications.
What type of energy does a hydraulic machine typically use?
A Kinetic energy
B Hydraulic energy
C Mechanical energy
D Electrical energy
Hydraulic machines use hydraulic energy, which is stored in pressurized fluid. This energy is harnessed to perform work such as lifting, driving machinery, or operating hydraulic systems in various applications like construction and power plants.
What is meant by flow distribution in hydraulic systems?
A Regulation of water temperature
B Control of water velocity
C The allocation of flow rate across various channels
D Measuring the pressure at different points
Flow distribution refers to how the total flow rate is allocated across different parts of a hydraulic system, such as multiple pipes or channels. Proper distribution is crucial for maintaining system efficiency and balance.
How is the efficiency of a turbine typically determined?
A By measuring water temperature
B By comparing input and output energy
C By calculating the pressure drop
D By comparing input and output energy
The efficiency of a turbine is determined by comparing the mechanical energy output with the hydraulic energy input. The greater the proportion of input energy converted to useful work, the higher the turbine’s efficiency.