Engineering :: Hydraulics Machines
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| 21. |
The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is |
| A. |
one-fourth |
B. |
one-half |
| C. |
three-fourth |
D. |
double |
Answer: Option B
Explanation:
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| 22. |
The overall efficiency for a Pelton wheel lies between |
| A. |
0.50 to 0.65 |
B. |
0.65 to 0.75 |
| C. |
0.75 to 0.85 |
D. |
0.85 to 0.90 |
Answer: Option D
Explanation:
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| 23. |
A double overhung Pelton wheel has |
| A. |
two jets |
B. |
two runners |
| C. |
four jets |
D. |
four runners |
Answer: Option B
Explanation:
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| 24. |
The width of the bucket for a Pelton wheel is generally |
| A. |
double |
B. |
three times |
| C. |
four times |
D. |
five times |
Answer: Option D
Explanation:
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| 25. |
The depth of the bucket for a Pelton wheel is generally |
| A. |
equal to |
B. |
1.2 times |
| C. |
1.8 times |
D. |
double |
Answer: Option B
Explanation:
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| 26. |
The jet ratio is defined as the ratio of the |
| A. |
diameter of jet to the diameter of Pelton wheel |
B. |
velocity of jet to the velocity of Pelton wheel |
| C. |
diameter of Pelton wheel to the diameter of jet |
D. |
velocity of Pelton wheel to the velocity of jet |
Answer: Option C
Explanation:
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| 27. |
Which of the following is not an impulse turbine? |
| A. |
Girad turbine |
B. |
Turgo turbine |
| C. |
Pelton wheel |
D. |
Kaplan turbine |
Answer: Option D
Explanation:
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| 28. |
The maximum number of jets, generally, employed in an impulse turbine without jet interference are |
Answer: Option C
Explanation:
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| 29. |
In a reaction turbine, the water enters the wheel under pressure and flows over the vanes. |
Answer: Option A
Explanation:
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| 30. |
In a reaction turbine, the pressure head of water, while flowing over the vanes, is converted into kinetic head before leaving the wheel. |
Answer: Option B
Explanation:
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