In an inward 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
Correct Answer :
C. The water enters the wheel at the outer periphery and then flows towards the centre of the wheel
Related Questions
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
For 450 m head of water, _________ shall be used.
Pelton wheel
Kaplan turbine
Francis turbine
None of these
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
Specific speed for reaction turbines ranges from
0 to 4.5
10 to 100
80 to 200
250 to 300
Which place in hydraulic turbine is most susceptible for cavitations?
Inlet of draft rube
Blade inlet
Guide blade
Penstock
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
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
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 hydraulic turbine depends upon
Speed and power developed
Discharge and power developed
Speed and head of water
Speed, power developed and head of water
Reaction turbines are used for
Low head
High head
High head and low discharge
Low head and high discharge
Casting of a centrifugal pump is designed so as to minimize
Friction loss
Cavitations
Static head
Loss of kinetic energy
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
In a centrifugal pump, the liquid enters the pump
At the top
At the bottom
At the canter
From sides
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
The specific speed of a centrifugal pump, delivering 750 litres of water per second against a head of 15 metres at 725 r.p.m., is
24.8 r.p.m.
48.2 r.p.m
82.4 r.p.m.
248 r.p.m
The jet ratio is defined as the ratio of the
Diameter of jet to the diameter of Pelton wheel
Velocity of jet to the velocity of Pelton wheel
Diameter of Pelton wheel to the diameter of jet
Velocity of Pelton wheel to the velocity of jet
Slip of a reciprocating pump is negative, when
Suction pipe is short and pump is running at low speeds
Delivery pipe is long and pump is running at high speeds
Suction pipe is short and delivery pipe is long and the pump is running at low speeds
Suction pipe is long and delivery pipe is short and the pump is running at high speeds
In a Francis turbine runner, the numbers of blades are generally between
2 to 4
4 to 8
8 to 16
16 to 24
For small discharge at high pressure, following pump is preferred
Centrifugal
Axial flow
Mixed flow
Reciprocating
In order to avoid cavitation in centrifugal pumps
The suction pressure should be high
The delivery pressure should be high
The suction pressure should be low
The delivery pressure should be low
A hydraulic coupling belongs to the category of
Power absorbing machines
Power developing machines
Energy transfer machines
Energy generating machines
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 is mainly due to
Low velocity
High velocity
Low pressure
High pressure
Overall 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
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.
Pressure intensifier increases the pressure in proportion to
Ratio of diameters
Square of ratio of diameters
Inverse ratio of diameters
Square of inverse ratio of diameters
In a reaction turbine, the draft tube is used
To run the turbine full
To prevent air to enter the turbine
To increase the head of water by an amount equal to the height of the runner outlet above the tail race
To transport water to downstream
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 maximum number of jets generally employed in impulse turbine without jet interference is
4
6
8
12
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