Geometric similarity is said to exist between the model and the prototype, if both of them
Have identical velocities
Are equal in size and shape
Are identical in shape, but differ only in size
Have identical forces
Correct Answer :
C. Are identical in shape, but differ only in size
Related Questions
A turbine develops 10000 kW under a head of 25 metres at 135 r.p.m. Its specific speed is
175.4 r.p.m.
215.5 r.p.m.
241.5 r.p.m.
275.4 r.p.m
The discharge through a reaction turbine ________ with the increase in unit speed.
Decreases
Increases
Remain same
None of these
In impulse Turbine, energy available at the inlet is in the form of
Potential Energy
Strain Energy
Kinetic energy
None of these
A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used?
Pelton wheel with one nozzle
Pelton wheel with two or more nozzles
Kaplan turbine
Francis turbine
The number of buckets on the periphery of a Pelton wheel is given by
(D/2d) + 5
(D/2d) + 10
(D/2d) + 15
(D/2d) + 20
In a centrifugal pump, the regulating valve is provided on the
Casing
Delivery pipe
Suction pipe
Impeller
The specific speed of turbine is defined as the speed of a unit
Of such a size that it delivers unit discharge at unit head
Of such a size that it delivers unit discharge at unit power
Of such a size that it requires unit power per unit head
Of such a size that it produces unit horse power with unit head
The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by
[2(Vr - v) v]/ Vr²
2(Vr + v) v]/ Vr²
[(Vr - v) v]/ Vr
[(Vr + v) v]/ Vr
Which of the following pump is successfully used for lifting water from deep wells?
Centrifugal pump
Reciprocating pump
Jet pump
Air lift pump
Axial flow pump is started with its delivery valve
Kept fully closed
Kept fully open
Irrespective of any position
Kept 50% open
Discharge of a centrifugal pump is (where N = Speed of the pump impeller)
Directly proportional to N
Inversely proportional to N
Directly proportional to N²
Inversely proportional to N²
In order to avoid cavitation in centrifugal pumps
The suction pressure should be high
The delivery pressure should be high
The suction pressure should be low
The delivery pressure should be low
A Francis turbine is used when the available head of water is
0 to 25 m
25 m to 250 m
Above 250 m
None of these
Multistage centrifugal pumps are used to obtain
High discharge
High head
Pumping of viscous fluids
High head and high discharge
The static head of a centrifugal pump is equal to the ________ of suction head and delivery head.
Product
Difference
Sum
None of these
Geometric similarity is said to exist between the model and the prototype, if both of them
Have identical velocities
Are equal in size and shape
Are identical in shape, but differ only in size
Have identical forces
Hydraulic accumulator is used for
Accumulating oil
Supplying large quantities of oil for very short duration
Generally high pressures to operate hydraulic machines
Supplying energy when main supply fails
In a centrifugal pump casing, the flow of water leaving the
Radial
Axial
Centrifugal
Vortex
The ratio of actual work available at the turbine to the energy imparted to the wheel is known as ________ efficiency.
Hydraulic
Mechanical
Overall
None of these
Which of the following is not an impulse turbine?
Girad turbine
Turgo turbine
Pelton wheel
Kaplan turbine
One horsepower is equal to
102 watts
75 watts
550 watts
735 watts
Which of the following is not a reaction turbine?
Fourneyron turbine
Journal turbine
Thomson's turbine
Pelton wheel
A Pelton wheel is
Tangential flow impulse turbine
Inward flow impulse turbine
Outward flow impulse turbine
Inward flow reaction turbine
In reaction turbine, draft tube is used
To transport water downstream without eddies
To convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
For safety of turbine
To increase flow rate
A hydraulic coupling belongs to the category of
Power absorbing machines
Power developing machines
Energy transfer machines
Energy generating machines
Indicator diagram of a reciprocating pump is a graph between
Flow vs. swept volume
Pressure in cylinder vs. swept volume
Flow vs. speed
Pressure vs. speed
In a centrifugal pump, the liquid enters the pump
At the top
At the bottom
At the canter
From sides
A ship with jet propulsion draws water through inlet orifices at right angles to the direction of its motion. The propelling force of the jet is (where a = Area of the jet, Vr = Relative velocity of the jet and ship = V + v, v = Velocity of the ship, and V = Velocity of the jet issuing from the ship)
waVr /g × (Vr + v)
waVr /g × (Vr - v)
waVr /g × (Vr + v)²
waVr /g × (Vr - v)²
Any change in load is adjusted by adjusting following parameter on turbine
Net head
Absolute velocity
Blade velocity
Flow
In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by
Designing new impeller
Trimming the impeller size to the required size by machining
Not possible
Some other alterations in the impeller