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.
Correct Answer :
B. Little above the tail race
Related Questions
Reaction turbines are used for
Low head
High head
High head and low discharge
Low head and high discharge
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
Which of the following pump is successfully used for lifting water from deep wells?
Centrifugal pump
Reciprocating pump
Jet pump
Air lift pump
A jet of water is striking at the centre of a curved vane moving with a uniform velocity in the direction of jet. For the maximum efficiency, the vane velocity is ________ of the jet velocity
One-half
One-third
Two-third
Three-fourth
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
For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred
Centrifugal
Axial flow
Reciprocating
Mixed flow
The Thomson's turbine is __________ reaction turbine.
An axial flow
An inward flow
An outward flow
A mixed flow
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 ship with jet propulsion draws water through inlet orifices at right angles to the direction of its motion. The propelling force of the jet is (where a = Area of the jet, Vr = Relative velocity of the jet and ship = V + v, v = Velocity of the ship, and V = Velocity of the jet issuing from the ship)
waVr /g × (Vr + v)
waVr /g × (Vr - v)
waVr /g × (Vr + v)²
waVr /g × (Vr - v)²
In reaction turbine, draft tube is used
To transport water downstream without eddies
To convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
For safety of turbine
To increase flow rate
In impulse Turbine, energy available at the inlet is in the form of
Potential Energy
Strain Energy
Kinetic energy
None of these
The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by
[2(Vr - v) v]/ Vr²
2(Vr + v) v]/ Vr²
[(Vr - v) v]/ Vr
[(Vr + v) v]/ Vr
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
If the ratios of all the corresponding linear dimensions are equal, then the model and the prototype are said to have
Geometric similarity
Kinematic similarity
Dynamic similarity
None of these
The impeller of a centrifugal pump may have
Volute casing
Volute casing with guide blades
Vortex casing
Any one of these
Which of the following pump is suitable for small discharge and high heads?
Centrifugal pump
Axial flow pump
Mixed flow pump
Reciprocating pump
Centrifugal pump is started with its delivery valve
Kept fully closed
Kept fully open
Irrespective of any position
Kept 50% open
The efficiency of a hydraulic press is given by (where W = Weight lifted by ram, P = Force applied on plunger, A = Area of ram, and a = Area of plunger)
(W/p) × (A/a)
(p/W) × (a/A)
(W/p) × (a/A)
(p/W) × (A/a)
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
According to fan laws, at constant pressure, the speed capacity and power vary
Directly as the air or gas density
Inversely as square root of density
Inversely as density
As square of density
Which of the following is not an impulse turbine?
Girad turbine
Turgo turbine
Pelton wheel
Kaplan turbine
Which of the following pump is successfully used for lifting water to the boilers?
Centrifugal pump
Reciprocating pump
Jet pump
Airlift pump
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
Discharge of a centrifugal pump is (where N = Speed of the pump impeller)
Directly proportional to N
Inversely proportional to N
Directly proportional to N²
Inversely proportional to N²
Puck up the wrong statement about centrifugal pump
Discharge a diameter
Head a speed²
Head a diameter
Power a speed⁴
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 axial flow fans and turbines, fluid enters and leaves as follows
Radially, axially
Axially, radially
Axially, axially
Radially, radially
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
The speed 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
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