Fluid Mechanics and Hydraulic Machines (3141906) MCQs

MCQs of Impact of Jet and Hydraulic Turbines

Showing 21 to 20 out of 30 Questions
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21.
In a reaction turbine, the draft tube is used
(a) to run the turbine full
(b) to prevent air to enter the turbine
(c) to increase the head of water by an amount equal to the height of the runner outlet above the tailrace
(d) to transport water to downstream
Answer:

Option (c)

22.
Which of the following statement is correct?
(a) In an impulse turbine, the water impinges on the bucket with pressure energy.
(b) In a reaction turbine, the water glides over the moving vanes with kinetic energy.
(c) In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure
(d) In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.
Answer:

Option (c)

23.
In an inward flow reaction turbine
(a) the water flows parallel to the axis of the wheel
(b) the water enters the entre of the wheel and then flows towards the outer periphery of the wheel
(c) the water enters the wheel at the outer periphery and then flows towards the centre of the wheel
(d) the flow of water is partly radial and partly axial
Answer:

Option (c)

24.
The flow ratio of the Francis turbine is defined as the ratio of the
(a) velocity of flow at the inlet to the theoretical jet velocity
(b) theoretical velocity of the jet to the velocity of flow at the inlet
(c) velocity of the runner at the inlet to the velocity of flow at the inlet
(d) none of the above
Answer:

Option (a)

25.
The power developed by a turbine is
(a) directly proportional to H12
(b) inversely proportional to H12
(c) directly proportional to H32
(d) inversely proportional to H32
Answer:

Option (c)

26.
The specific speed of a turbine is given by the equation
(a) NPH32
(b) NPH2
(c) NPH54
(d) NPH3
Answer:

Option (c)

27.
The speed of an imaginary turbine, identical with the given turbine, which will develop a unit power under a unit head, is known as
(a) normal speed
(b) unit speed
(c) specific speed
(d) none of these
Answer:

Option (c)

28.
Which of the following turbine is preferred for a specific speed of 60 to 300 rpm?
(a) Pelton wheel
(b) Francis turbine
(c) Kaplan turbine
(d) none of these
Answer:

Option (b)

29.
Which of the following turbine is preferred for 0 to 25 m head of water?
(a) Pelton wheel
(b) Kaplan turbine
(c) Francis turbine
(d) none of these
Answer:

Option (b)

30.
The cavitation in a hydraulic machine
(a) cause noise and vibration of various parts
(b) reduces the discharge of a turbine
(c) causes sudden drop in power output and efficiency
(d) all of the above
Answer:

Option (d)

Showing 21 to 20 out of 30 Questions
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