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
Correct Answer :
B. Nearly horizontal
Related Questions
For starting an axial flow pump, its delivery valve should be
Closed
Open
Depends on starting condition and flow desired
Could be either open or closed
The overall efficiency of a reaction turbine is the ratio of
Power produced by the turbine to the energy actually supplied by the turbine
Actual work available at the turbine to the energy imparted to the wheel
Workdone on the wheel to the energy (or head of water) actually supplied to the turbine
None of the above
In impulse Turbine, energy available at the inlet is in the form of
Potential Energy
Strain Energy
Kinetic energy
None of these
A turbine pump is basically a centrifugal pump equipped additionally with
Adjustable blades
Backward curved blades
Vaned diffusion casing
Inlet guide blades
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
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 would discharge
Same quantity of liquid
0.75 Q
Q/0.75
1.5 Q
Which type of the pump is different from others in the same group?
Screw pump
Gear pump
Cam and piston pump
Plunger pump
Medium specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
Any one of the above
The mechanical efficiency of an impulse turbine is
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
An impulse turbine is used for
Low head of water
High head of water
Medium head of water
High discharge
For 450 m head of water, _________ shall be used.
Pelton wheel
Kaplan turbine
Francis turbine
None of these
According to fan laws, for fans having constant wheel diameter, the air or gas capacity varies
Directly as fan speed
Square of fan speed
Cube of fan speed
Square root of fan speed
The efficiency of a Pelton wheel working under constant head ________ with the increase in power.
Remain same
Increases
Decreases
None of these
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
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 flow ratio in case of Francis turbine varies from
0.15 to 0.3
0.4 to 0.5
0.6 to 0.9
1 to 1.5
Medium specific speed of turbine implies it is
Propeller turbine
Francis turbine
Impulse turbine
Any one of the above
Which of the following pump is successfully used for lifting water from deep wells?
Centrifugal pump
Reciprocating pump
Jet pump
Air lift pump
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 optimum value of vane exit angle for a centrifugal pump impeller is
10-15°
20-25°
30-40°
50-60°
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
A hydraulic accumulator is a device used to store ________ energy which may be supplied to a machine later on.
Strain
Pressure
Kinetic
None of these
Casting of a centrifugal pump is designed so as to minimize
Friction loss
Cavitations
Static head
Loss of kinetic energy
By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. The saving in case of a double acting reciprocating pump is
39.2 %
48.8 %
84.8 %
88.4 %
Which of the following is not an impulse turbine?
Girad turbine
Turgo turbine
Pelton wheel
Kaplan turbine
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
In a reciprocating pump, air vessels are used to
Smoothen the flow
Reduce suction head
Increase delivery head
Reduce acceleration head
In axial flow fans and turbines, fluid enters and leaves as follows
Radially, axially
Axially, radially
Axially, axially
Radially, radially
Dynamic 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
None of the above
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