For 450 m head of water, _________ shall be used.
Pelton wheel
Kaplan turbine
Francis turbine
None of these
Correct Answer :
A. Pelton wheel
Related Questions
Which of the following pump is suitable for small discharge and high heads?
Centrifugal pump
Axial flow pump
Mixed flow pump
Reciprocating pump
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 unit speed of the turbine runner is
N/√H
N/H
N/H3/2
N/H²
The unit discharge through the turbine is
Q/√H
Q/H
Q/H3/2
Q/H²
Power required to drive a centrifugal pump is directly proportional to ________ of its impeller.
Diameter
Square of diameter
Cube of diameter
Fourth power of diameter
Saving of work done and power by fitting an air vessel to double acting reciprocating pump is of the order of
39.2 %
49.2 %
68.8 %
84.8 %
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 ratio of quantity of liquid discharged per second from the pump to the quantity of liquid passing per second through the impeller is known as
Manometric efficiency
Mechanical efficiency
Overall efficiency
Volumetric efficiency
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
Discharge (Q) of a centrifugal pump is given by (where D = Diameter of impeller at inlet, b = Width of impeller at inlet, and Vf = Velocity of flow at inlet)
Q = π.D.Vf
Q = π.b.Vf
Q = π.D.bf.V
Q = D.b.Vf
A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit speed of the wheel is
10 r.p.m.
20 r.p.m.
40 r.p.m.
80 r.p.m.
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 optimum value of vane exit angle for a centrifugal pump impeller is
10-15°
20-25°
30-40°
50-60°
A hydraulic press is a device used
To store pressure energy which may be supplied to a machine later on
To increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure
To lift larger load by the application of a comparatively much smaller force
All of the above
The flow ratio of Francis turbine is defined as the ratio of the
Velocity of flow at inlet to the theoretical jet velocity
Theoretical velocity of jet to the velocity of flow at inlet
Velocity of runner at inlet to the velocity of flow at inlet
None of the above
By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. This saving in case of a single acting reciprocating pump is
39.2 %
48.8 %
84.8 %
88.4 %
Discharge of a centrifugal pump is
Directly proportional to diameter of its impeller
Inversely proportional to diameter of its impeller
Directly proportional to (diameter)² of its impeller
Inversely proportional to (diameter)² of its impeller
The discharge through a reaction turbine with increase in unit speed
Increases
Decreases
Remain unaffected
First increases and then decreases
In a centrifugal pump, the liquid enters the pump
At the top
At the bottom
At the canter
From sides
A hydraulic ram is a device used to
Store the energy of water
Increase the pressure of water
To lift water from deep wells
To lift small quantity of water to a greater height when a large quantity of water is available at a smaller height
Saving of work done and power by fitting an air vessel to single acting reciprocating pump is of the order of
39.2 %
49.2 %
68.8 %
84.8 %
The Thomson's turbine is __________ reaction turbine.
An axial flow
An inward flow
An outward flow
A mixed flow
The specific speed (Ns) of a centrifugal pump is given by
(N√Q)/H2/3
(N√Q)/H3/4
(N√Q)/H
(N√Q)/H5/4
If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water, the horse power required will be
Same
0.75 B.H.P.
B.H.P./0.75
1.5 B.H.P.
The cavitation in a hydraulic machine is mainly due to
Low velocity
High velocity
Low pressure
High pressure
The specific speed of a turbine is given by the equation
N√P / H3/2
N√P / H²
N√P / H5/4
N√P / H3
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
Air vessels in reciprocating pump are used to
Smoothen flow
Reduce acceleration to minimum
Increase pump efficiency
Save pump from cavitations
The impeller of a centrifugal pump may have
Volute casing
Volute casing with guide blades
Vortex casing
Any one of these
Guide angle as per the aerofoil theory of Kaplan turbine blade design is defined as the angle between
Lift and resultant force
Drag and resultant force
Lift and tangential force
Lift and drag