When a piping system is made up primarily of vertical lift and very little pipe friction, the pump characteristics should be
Horizontal
Nearly horizontal
Steep
First rise and then fall
Correct Answer :
C. Steep
Related Questions
Medium specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
Any one of the above
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
Which of the following hydraulic unit is used for transmitting increased or decreased torque to the driven shaft?
Hydraulic ram
Hydraulic intensifier
Hydraulic torque converter
Hydraulic accumulator
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
If the net positive suction head (NPSH) requirement for the pump is not satisfied, then
No flow will take place
Cavitation will be formed
Efficiency will be low
Excessive power will be consumed
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 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 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
In a reciprocating pump, air vessels are used to
Smoothen the flow
Reduce suction head
Increase delivery head
Reduce acceleration head
According to fan laws, for fans having constant wheel diameter, the pressure varies
Directly as fan speed
Square of fan speed
Cube of fan speed
Square root of fan speed
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 %
Low specific speed of turbine implies it is
Propeller turbine
Francis turbine
Impulse turbine
Any one of the above
Francis, Kaplan and propeller turbines fall under the category of
Impulse turbines
Reaction turbines
Axial flow turbines
Mixed flow turbines
Low specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
None of the above
The speed of an imaginary turbine, identical with the given turbine, which will develop a unit power under a unit head, is known as
Normal speed
Unit speed
Specific speed
None of these
The undershot water wheels are those in which
The wheel runs entirely by the weight of water
The wheel runs entirely by the impulse of water
The wheel runs partly by the weight of water and partly by the impulse of water
None of the above
The centrifugal pump preferred for a specific speed between 80 to 160 r.p.m. 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 mixed flow at outlet
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
Multistage centrifugal pumps are used to
Give high discharge
Produce high heads
Pump viscous fluids
All of these
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 efficiency of a Pelton wheel working under constant head ________ with the increase in power.
Remain same
Increases
Decreases
None of these
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 %
The function of guide vanes in a reaction turbine is to
Allow the water to enter the runner without shock
Allow the water to flow over them, without forming eddies
Allow the required quantity of water to enter the turbine
All 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
The force exerted (in Newton) by a jet of water impinging normally on a fixed plate is (where w = Specific weight of water in N/m3, a = Crosssectional area of jet in m², and V = Velocity of jet in m/s)
waV / 2g
waV / g
waV² / 2g
waV² / g
When a piping system is made up primarily of vertical lift and very little pipe friction, the pump characteristics should be
Horizontal
Nearly horizontal
Steep
First rise and then fall
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.
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 %
The discharge through a reaction turbine ________ with the increase in unit speed.
Decreases
Increases
Remain same
None of these
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 %