For small discharge at high pressure, following pump is preferred
Centrifugal
Axial flow
Mixed flow
Reciprocating
Correct Answer :
D. Reciprocating
Related Questions
Axial flow pump is started with its delivery valve
Kept fully closed
Kept fully open
Irrespective of any position
Kept 50% open
According to fan laws, at constant speed and capacity, the pressure and power vary
Directly as the air or gas density
Inversely as square root of density
Inversely as density
As square of density
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
In centrifugal pumps, maximum efficiency is obtained when the blades are
Straight
Bent forward
Bent backward
Radial
Which type of the pump is different from others in the same group?
Screw pump
Gear pump
Cam and piston pump
Plunger pump
The maximum number of jets, generally, employed in an impulse turbine without jet interference are
Two
Four
Six
Eight
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
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 %
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 power of the wheel is
0.25 kW
0.75 kW
1.75 kW
3.75 kW
The discharge through a turbine is
Directly proportional to H1/2
Inversely proportional to H1/2
Directly proportional to H3/2
Inversely proportional to H3/2
The Thomson's turbine is __________ reaction turbine.
An axial flow
An inward flow
An outward flow
A mixed flow
Which of the following statement is correct?
The centrifugal pump is suitable for large discharge and smaller heads.
The centrifugal pump requires less floor area and simple foundation as compared to reciprocating pump.
The efficiency of centrifugal pump is less as compared to reciprocating pump.
All of the above
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 %
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 %
In an outward flow reaction turbine
The water flows parallel to the axis of the wheel
The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel
The water enters the wheel at the outer periphery and then flows towards the centre of the wheel
The flow of water is partly radial and partly axial
The runaway speed of a hydraulic turbine is the speed
At full load
At which there will be no damage to the runner
Corresponding to maximum overload permissible
At which the turbine will run freely without load
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 %
Francis turbine is best suited for
Medium head application from 24 to 180 m
Low head installation up to 30 m
High head installation above 180 m
All types of heads
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 discharge of wheel is
0.25 m3/s
0.5 m3/s
1.5 m3/s
2.5 m3/s
Low specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
None of the above
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
The power produced by the reaction turbine is ________ to the head of water.
Directly proportional
Inversely proportional
4th power
None of these
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
Impulse turbine is generally fitted
At the level of tail race
Little above the tail race
Slightly below the tail race
About 2.5 m above the tail race to avoid cavitations.
The working of which of the following hydraulic units is based on Pascal's law?
Air lift pump
Jet pump
Hydraulic coupling
Hydraulic press
In a centrifugal pump casing, the flow of water leaving the impeller, is
Rectilinear flow
Radial flow
Free vortex motion
Forced vortex
Low specific speed of turbine implies it is
Propeller turbine
Francis turbine
Impulse turbine
Any one of the above
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
High specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
Any one of the above
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