Discussion
Home ‣ Mechanical Engineering ‣ Hydraulic Machines Comments
- Question
If V1 and V2 are the velocities of water at inlet and outlet of the draft tube respectively, then the efficiency of a draft tube is
Options- A.
- B.
- C.
- D.
- Correct Answer
-
- 1. If the Francis turbine is run below 50 percent head for a long period, it will not only lose its efficiency but also the cavitation danger will become more serious.
Options- A. Agree
- B. Disagree Discuss
- 2. If the ratio's of the corresponding forces acting at corresponding points are equal, then the model and the prototype are said to have.
Options- A. geometric similarity
- B. kinematic similarity
- C. dynamic similarity
- D. none of these Discuss
- 3. Dynamic similarity is said to exist between the model and the prototype, if both of them
Options- A. have identical velocities
- B. are equal in size and shape
- C. are identical in shape, but differ only in size
- D. none of the above Discuss
- 4. The cavitation in reaction turbines is avoided, to a great extent by
Options- A. installing the turbine below the tail race level
- B. using stainless steel runner of the turbine
- C. providing highly polished blades to the runner
- D. all of the above Discuss
- 5. In a mixed flow centrifugal pump, the flow through the impeller is a combination of radial and axial flows.
Options- A. Correct
- B. Incorrect Discuss
- 6. The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is __________ of the jet velocity,
Options- A. one-fourth
- B. one-half
- C. three-fourth
- D. double Discuss
- 7. A hydraulic intensifier is a device used to increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure.
Options- A. Correct
- B. Incorrect Discuss
- 8. Which of the following statement is correct as regard to water wheels?
Options- A. They have slow speeds.
- B. They are suitable even for low water heads.
- C. They give constant efficiency, even if the discharge is not constant
- D. all of the above Discuss
- 9. The hydraulic efficiency of an impulse turbine is the
Options- A. ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
- B. ratio of the actual work available at the turbine to the energy imparted to the wheel
- C. ratio of the work done on the wheel to the energy of the jet
- D. none of the above Discuss
- 10. Which of the following statement is wrong?
Options- A. The reaction turbines are used for low head and high discharge.
- B. The angle of taper on draft tube is less than 8°.
- C. An impulse turbine is generally fitted slightly above the tail race.
- D. A Francis turbine is an impulse turbine. Discuss
Hydraulic Machines problems
Search Results
Correct Answer: Agree
Correct Answer: dynamic similarity
Correct Answer: none of the above
Correct Answer: all of the above
Correct Answer: Correct
Correct Answer: one-half
Correct Answer: Correct
Correct Answer: all of the above
Correct Answer: ratio of the work done on the wheel to the energy of the jet
Correct Answer: A Francis turbine is an impulse turbine.
Comments
There are no comments.More in Mechanical Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.