The unit discharge through the turbine is
Q/√H
Q/H
Q/H3/2
Q/H²
Correct Answer :
A. Q/√H
Related Questions
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
Head developed by a centrifugal pump is
Proportional to diameter of impeller
Proportional to speed of impeller
Proportional to diameter and speed of impeller
None of the above
Manometric head, in case of a centrifugal pump, is equal to
Suction lift + Loss of head in suction pipe due to friction + Delivery lift + Loss of head in delivery pipe due to friction + Velocity head in the delivery pipe
Workdone per kN of water Losses within the impeller
Energy per kN at outlet of impeller Energy per kN at inlet of impeller
All of the above
Reaction turbines are used for
Low head
High head
High head and low discharge
Low head and high discharge
The angle of taper on draft tube is
Greater than 15°
Greater than 8°
Greater than 5°
Less than 8°
The speed of a turbine runner is
Directly proportional to H1/2
Inversely proportional to H1/2
Directly proportional to H3/2
Inversely proportional to H3/2
The unit discharge through the turbine is
Q/√H
Q/H
Q/H3/2
Q/H²
According to fan laws, at constant pressure, the speed capacity and power vary
Directly as the air or gas density
Inversely as square root of density
Inversely as density
As square of density
The maximum efficiency of jet propulsion of a ship with inlet orifices at right angles to the direction of motion of ship, is
40 %
50 %
60 %
80 %
The specific speed of a hydraulic turbine depends upon
Speed and power developed
Discharge and power developed
Speed and head of water
Speed, power developed and head of water
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
Low specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
None of the above
The discharge through a reaction turbine ________ with the increase in unit speed.
Decreases
Increases
Remain same
None of these
The overall efficiency for a Pelton wheel lies between
0.50 to 0.65
0.65 to 0.75
0.75 to 0.85
0.85 to 0.90
The force exerted by a jet of water (in a direction normal to flow) impinging on a fixed plate inclined at an angle θ with the jet is
waV/2g × sinθ
waV/g × sinθ
waV²/2g × sin2θ
waV²/g × sinθ
The hydraulic efficiency of an impulse turbine is the
Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
Ratio of the actual work available at the turbine to the energy imparted to the wheel
Ratio of the work done on the wheel to the energy of the jet
None of the above
The specific speed from 160 to 500 r.p.m. of a centrifugal pump indicates that the pump is
Slow speed with radial flow at outlet
Medium speed with radial flow at outlet
High speed with radial flow at outlet
High speed with axial flow at outlet
Which of the following pump is successfully used for lifting water from deep wells?
Centrifugal pump
Reciprocating pump
Jet pump
Air lift pump
High specific speed of turbine implies it is
Propeller turbine
Francis turbine
Impulse turbine
None of the above
A centrifugal pump will start delivering liquid only when the pressure rise in the impeller is equal to the
Kinetic head
Velocity head
Manometric head
Static head
The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is _______ of the jet velocity,
One-fourth
One-half
Three-fourth
Double
The force exerted by a jet of water impinging normally on a plate which due to the impact of jet, moves in the direction of jet with a velocity v is
[wa (V - v)]/2g
[wa (V - v)]/g
[wa (V - v)²]/2g
[wa (V - v²)]/g
When a piping system is made up primarily of friction head and very little of vertical lift, then pump characteristics should be
Horizontal
Nearly horizontal
Steep
First rise and then fall
The specific speed of a turbine is the speed of an imaginary turbine, identical with the given turbine, which
Delivers unit discharge under unit head
Delivers unit discharge under unit speed
Develops unit power under unit head
Develops unit power under unit speed
Francis, Kaplan and propeller turbines fall under the category of
Impulse turbines
Reaction turbines
Axial flow turbines
Mixed flow turbines
The unit power developed by a turbine is (where P = Power developed by the turbine under a head of water (H).
P/ √H
P/ H
P/ H3/2
P/ H²
The cavitation in a hydraulic machine
Causes noise and vibration of various parts
Reduces the discharge of a turbine
Causes sudden drop in power output and efficiency
All of the above
The maximum hydraulic efficiency of an impulse turbine is (where φ = Angle of blade tip at outlet)
(1 + cos φ)/2
(1 - cos φ)/2
(1 + sin φ)/2
(1 - sin φ)/2
In a Kaplan turbine runner, the numbers of blades are generally between
2 to 4
4 to 8
8 to 16
16 to 24
Mechanical efficiency of a centrifugal pump is the ratio of
Energy available at the impeller to the energy supplied to the pump by the prime mover
Actual workdone by the pump to the energy supplied to the pump by the prime mover
Energy supplied to the pump to the energy available at the impeller
Manometric head to the energy supplied by the impeller per kN of water