The power produced by the reaction turbine is ________ to the head of water.
Directly proportional
Inversely proportional
4th power
None of these
Correct Answer :
A. Directly proportional
Related Questions
Runaway speed of a hydraulic turbine is
Full load speed
The speed at which turbine runner will be damaged
The speed if the turbine runner is allowed to revolve freely without load and with the wicket gates wide open
The speed corresponding to maximum overload permissible
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 maximum number of jets generally employed in impulse turbine without jet interference is
4
6
8
12
High specific speed of a pump implies it is
Centrifugal pump
Mixed flow pump
Axial flow pump
Any one of the above
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
Head developed by a centrifugal pump depends on
Impeller diameter
Speed
Fluid density
Both (A) and (B) above
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
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
The cavitation in reaction turbines is avoided, to a great extent by
Installing the turbine below the tail race level
Using stainless steel runner of the turbine
Providing highly polished blades to the runner
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 Thomson's turbine is __________ reaction turbine.
An axial flow
An inward flow
An outward flow
A mixed flow
The hydraulic 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 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
Discharge of a centrifugal pump is
Directly proportional to diameter of its impeller
Inversely proportional to diameter of its impeller
Directly proportional to (diameter)² of its impeller
Inversely proportional to (diameter)² of its impeller
Reaction turbines are used for
Low head
High head
High head and low discharge
Low head and high discharge
Slip of a reciprocating pump is defined as the
Ratio of actual discharge to the theoretical discharge
Sum of actual discharge and the theoretical discharge
Difference of theoretical discharge and the actual discharge
Product of theoretical discharge and the actual discharge
Casting of a centrifugal pump is designed so as to minimize
Friction loss
Cavitations
Static head
Loss of kinetic energy
Which of the following is not a reaction turbine?
Fourneyron turbine
Journal turbine
Thomson's turbine
Pelton wheel
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
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
A Pelton wheel is
Tangential flow impulse turbine
Inward flow impulse turbine
Outward flow impulse turbine
Inward flow reaction turbine
A hydraulic press is a device used
To store pressure energy which may be supplied to a machine later on
To increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure
To lift larger load by the application of a comparatively much smaller force
All of the above
Motion of a liquid in a volute casing of a centrifugal pump is an example of
Rotational flow
Radial
Forced spiral vortex flow
Spiral vortex flow
For centrifugal pump impeller, the maximum value of the vane exit angle is
10° to 15°
15° to 20°
20° to 25°
25° to 30°
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
Delivery head of a centrifugal pump is
Directly proportional to N
Inversely proportional to N
Directly proportional to N²
Inversely proportional to N²
Braking jet in an impulse turbine is used
To break the jet of water
To bring the runner to rest in a short time
To change the direction of runner
None of these
Which of the following pump is successfully used for lifting water to the turbines?
Centrifugal pump
Reciprocating pump
Jet pump
Air lift pump
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
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 %
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 speed of the wheel is
10 r.p.m.
20 r.p.m.
40 r.p.m.
80 r.p.m.