A hydraulic pump takes mechanical energy (from an engine or motor) and converts it into hydraulic energy by pressurizing a fluid. This pressurized fluid is then used to power various hydraulic systems.
Which type of pump requires priming before operation?
A Centrifugal pump
B Gear pump
C Reciprocating pump
D Jet pump
Centrifugal pumps require priming because they cannot handle air and need to be filled with liquid before starting. Without priming, the pump cannot create the necessary suction to draw fluid.
What does a hydraulic intensifier do?
A Increases fluid velocity
B Decreases turbulence
C Increases fluid pressure
D Reduces flow rate
A hydraulic intensifier increases fluid pressure by reducing flow rate. It is used in hydraulic presses and other applications where high pressure is required but flow rate is not a major concern.
What is the function of guide vanes in a Francis turbine?
A Control water flow direction
B Convert kinetic energy to pressure energy
C Increase turbine speed
D Store energy
Guide vanes in a Francis turbine direct water flow at the correct angle to the runner blades. This ensures efficient energy transfer and prevents losses due to improper flow direction.
What happens to pressure energy in a reaction turbine?
A Remains constant
B Converts into kinetic energy
C Increases velocity
D Converts into heat energy
In a reaction turbine, pressure energy of water is gradually converted into kinetic energy as it passes through the turbine. This helps drive the turbine blades and generate mechanical energy.
What is the purpose of an air vessel in a reciprocating pump?
A Increase pump speed
B Store excess water
C Prevent water hammer
D Reduce flow fluctuations
An air vessel in a reciprocating pump reduces fluctuations in discharge by smoothing out the pressure variations. This improves efficiency and reduces the load on the pump components.
Which factor influences cavitation in a pump the most?
A Low pressure
B High velocity
C High flow rate
D Large pipe diameter
Cavitation occurs when local pressure in a pump drops below the vapor pressure of the liquid, causing vapor bubbles to form. These bubbles collapse violently, damaging pump impellers.
What is the function of a penstock in a hydropower plant?
A Store water
B Increase turbine speed
C Control water flow to turbines
D Measure flow rate
A penstock is a large pipeline that directs high-pressure water to turbines in a hydropower plant. It controls the water flow rate and prevents energy losses before entering the turbine.
What type of turbine is used in tidal power plants?
A Kaplan turbine
B Bulb turbine
C Francis turbine
D Pelton wheel
Bulb turbines are used in tidal power plants because they can operate in both directions, making them suitable for fluctuating tidal flows. They are highly efficient in low-head conditions.
What is the main cause of water hammer?
A Sudden valve closure
B High flow rate
C Pipe leakage
D Increased temperature
Water hammer occurs when a valve is suddenly closed, causing the moving water to stop abruptly. This creates a high-pressure shockwave that can damage pipes and hydraulic components.
What happens in a hydraulic jump?
A Energy is stored
B Velocity decreases, depth increases
C Pressure drops suddenly
D Flow becomes laminar
A hydraulic jump occurs when fast-moving water transitions to a slower-moving state, causing an increase in depth and turbulence. This process dissipates energy and is used for flow control in open channels.
What does “Net Positive Suction Head (NPSH)” indicate in a pump?
A Maximum suction lift
B Pump efficiency
C Available pressure to avoid cavitation
D Maximum discharge
NPSH is the minimum pressure required at the suction side of a pump to prevent cavitation. If NPSH is too low, vapor bubbles form, leading to damage and reduced efficiency.
In which hydraulic system is a “fluid coupling” used?
A Power transmission
B Flow control
C Water storage
D Pressure measurement
A fluid coupling is used in hydraulic systems to transmit power between rotating shafts using fluid motion. It provides smooth acceleration and protects machinery from shock loads.
What does the term “hydraulic gradient” refer to?
A Water depth in a canal
B Slope of a water surface
C Pressure drop in a pipe
D Velocity of fluid
The hydraulic gradient represents the slope of a water surface or pressure head along a flow path. It determines the direction and rate of fluid movement in an open channel or pipe.
What is the purpose of “governing” in a Kaplan turbine?
A Control blade angle
B Increase flow rate
C Store hydraulic energy
D Reduce power output
In a Kaplan turbine, governing involves adjusting the blade angle to match varying flow conditions. This maintains efficiency and ensures a steady power output under different water flow rates.