Discussion
Home ‣ Mechanical Engineering ‣ Steam Nozzles and Turbines Comments
- Question
A single stage turbine is not used because it requires large reduction gearing due to very high rotational speed.
Options- A. Agree
- B. Disagree
- Correct Answer
- Agree
- 1. The effect of bleeding is that
Options- A. it increases the thermodynamic efficiency of the turbine
- B. boiler is supplied with hot water
- C. it decreases the power developed by the turbine
- D. all of the above Discuss
- 2. In an ideal impulse turbine, the
Options- A. absolute velocity at the inlet of moving blade is equal to that at the outlet
- B. relative velocity at the inlet of the moving blade is equal to that at the outlet
- C. axial velocity at inlet is equal to that at the outlet
- D. whirl velocity at inlet is equalto that at the outlet Discuss
- 3. A nozzle is said to be a convergent-divergent nozzle, when the cross-section of a nozzle first decreases from its entrance to throat and then increases from its throat to exit.
Options- A. True
- B. False Discuss
- 4. In an impulse turbine, steam expands
Options- A. wholly in blades
- B. wholly in nozzle
- C. partly in the nozzle and partly in blades
- D. none of these Discuss
- 5. In a Parson's turbine stage, blade velocity is 320 m/s at the mean radius and rotor blade exit angle is 30°. For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the rotor will be
Options- A. 160/3 m/s
- B. 320/3 m/s
- C. 640/3 m/s
- D. 640 m/s Discuss
- 6. Which of the following statement is wrong?
Options- A. The critical pressure gives the velocity of steam at the throat equal to the velocity of sound.
- B. The flowin the convergent portion of the nozzle is sub-sonic.
- C. The flow in the divergent portion of the nozzle is super-sonic.
- D. To increase the velocity of steam above sonic velocity (super-sonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary. Discuss
- 7. During flow through a nozzle, no heat is supplied or rejected by the steam.
Options- A. Agree
- B. Disagree Discuss
- 8. Which of the following statement is correct?
Options- A. The efficiency of steam turbines is greater than steam engines.
- B. A flywheel is a must for steam turbine.
- C. The turbine blades do not change the direction of steam issuing from the nozzle
- D. The pressure of steam, in reaction turbines, is increased in fixed blades as well as in moving blades Discuss
- 9. Steam turbines may be classified according to
Options- A. direction of steam flow
- B. number of stages
- C. mode of steam action
- D. all of these Discuss
- 10. In a nozzle, the effect of supersaturation is to increase the dryness fraction of steam.
Options- A. Yes
- B. No Discuss
Steam Nozzles and Turbines problems
Search Results
Correct Answer: all of the above
Correct Answer: relative velocity at the inlet of the moving blade is equal to that at the outlet
Correct Answer: True
Correct Answer: wholly in nozzle
Correct Answer: 640/3 m/s
Correct Answer: To increase the velocity of steam above sonic velocity (super-sonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary.
Correct Answer: Agree
Correct Answer: The efficiency of steam turbines is greater than steam engines.
Correct Answer: all of these
Correct Answer: Yes
Comments
There are no comments.More in Mechanical Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.