What is the primary purpose of a hydraulic turbine?
A To store water
B To increase water pressure
C To convert hydraulic energy into mechanical energy
D To measure fluid velocity
A hydraulic turbine is a machine that converts the energy of flowing water into mechanical energy. This mechanical energy can then be used directly for work or further converted into electricity in power plants.
What type of fluid flow occurs in an open channel?
A Free-surface flow
B Pressurized flow
C Laminar flow
D Supersonic flow
Open channel flow refers to fluid movement where the flow has a free surface exposed to the atmosphere, such as in rivers and canals. Unlike pressurized flow, it is influenced by gravity rather than pipe constraints.
What happens during a water hammer event?
A Pressure drops suddenly
B A shock wave travels through the pipe
C Fluid speed increases
D Water temperature rises
Water hammer occurs when the flow of water is suddenly stopped or changed, causing a pressure wave to travel through the pipe. This can lead to severe stress, pipe damage, and noise in the system.
What is the function of a draft tube in a reaction turbine?
A Increases fluid velocity
B Controls water flow
C Reduces cavitation
D Converts kinetic energy to pressure energy
A draft tube in a reaction turbine allows water to exit at a lower velocity by converting its kinetic energy into pressure energy. This increases the efficiency of energy extraction from the fluid.
What is the main advantage of a Pelton wheel turbine?
A Efficient at high heads
B Works at low head
C Handles high flow rates
D Requires large space
The Pelton wheel is an impulse turbine designed for high-head, low-flow conditions. It efficiently converts the kinetic energy of water jets into rotational energy by directing high-speed water onto the buckets.
What is the term for energy loss due to friction in a pipeline?
A Turbulence loss
B Head loss
C Velocity loss
D Pressure drop
Head loss occurs due to friction between the fluid and the pipe walls. It reduces the available energy for flow, requiring additional pumping power to maintain fluid movement through the pipeline.
Which device is used to measure the velocity of flow in an open channel?
A Pitot tube
B Orifice meter
C Venturi meter
D Float-type flowmeter
A Pitot tube is used to measure fluid velocity by capturing the difference between static and dynamic pressure. It is commonly used in open channels, aerodynamics, and pipe flow measurement.
What is the role of a spillway in a dam?
A Stores water
B Generates power
C Releases excess water
D Controls water quality
Spillways are designed to safely discharge excess water from reservoirs to prevent overflow and structural failure. They protect the dam by maintaining water levels during floods or heavy rainfall.
What type of turbine is commonly used for medium-head applications?
A Pelton turbine
B Francis turbine
C Kaplan turbine
D Cross-flow turbine
The Francis turbine is widely used for medium-head applications because it efficiently converts water energy into mechanical energy through a combination of impulse and reaction principles.
What is the primary function of governing in turbines?
A To increase turbine efficiency
B To improve power transmission
C To reduce head loss
D To maintain constant speed
Governing in turbines regulates the flow of water to ensure the turbine runs at a constant speed. This prevents fluctuations in power output and maintains the stability of the power grid.
What is cavitation in hydraulic machines?
A Formation of air bubbles
B Sudden temperature rise
C Increase in water pressure
D Loss of fluid velocity
Cavitation occurs when local pressure drops below the vapor pressure of the liquid, causing vapor bubbles to form. These bubbles collapse violently, leading to material erosion and reduced efficiency in hydraulic machines.
What is the purpose of pump priming?
A To adjust turbine speed
B To remove air from the pump
C To fill the reservoir
D To regulate fluid density
Priming a pump ensures that all air is removed before operation, allowing the pump to function properly. If air remains inside, it can prevent fluid from being drawn in and cause the pump to fail.
What is “specific speed” in hydraulic machines?
A A dimensionless number for performance comparison
B Speed of turbine in RPM
C Maximum water velocity
D Minimum operating speed
Specific speed is a dimensionless parameter used to compare the performance of different pumps or turbines. It helps in selecting the right machine based on its head, flow rate, and rotational speed.
What is the function of a hydraulic gate in a canal?
A Increases water velocity
B Stores excess water
C Controls water flow
D Measures fluid density
Hydraulic gates are used in canals and reservoirs to regulate water flow. They help in irrigation, flood control, and hydropower generation by adjusting the amount of water passing through.
What happens to fluid velocity in a Venturi meter?
A Increases in the throat
B Decreases at the inlet
C Remains constant
D Drops to zero
A Venturi meter works on Bernoulli’s principle, where fluid velocity increases in the narrow throat section due to pressure reduction. This is used to measure the flow rate accurately in hydraulic systems.