Discussion
Home ‣ Mechanical Engineering ‣ Steam Nozzles and Turbines Comments
- Question
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
- Correct Answer
- 640/3 m/s
- 1. If the critical pressure ratio for steam is 0.546, then the steam is initially
Options- A. wet steam
- B. dry saturated steam
- C. superheated steam
- D. none of these Discuss
- 2. In velocity compounding of an impulse turbine, the expansion of steam takes place in a nozzle or a set of nozzles from the boiler pressure to condenser pressure.
Options- A. True
- B. False Discuss
- 3. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ number of stages are required.
Options- A. more
- B. less Discuss
- 4. De-Laval turbine is a
Options- A. simple impulse turbine
- B. simple reaction turbine
- C. impulse-reaction turbine
- D. none of these Discuss
- 5. The effect of supersaturation is that the
Options- A. mass of the steam discharged increases
- B. entropy and specific volume of the steam increases
- C. exit velocity of steam reduces
- D. all of these Discuss
- 6. 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
- 7. 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
- 8. 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
- 9. 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
- 10. A single stage turbine is not used because it requires large reduction gearing due to very high rotational speed.
Options- A. Agree
- B. Disagree Discuss
Steam Nozzles and Turbines problems
Search Results
Correct Answer: superheated steam
Correct Answer: True
Correct Answer: less
Correct Answer: simple impulse turbine
Correct Answer: all of these
Correct Answer: wholly in nozzle
Correct Answer: True
Correct Answer: relative velocity at the inlet of the moving blade is equal to that at the outlet
Correct Answer: all of the above
Correct Answer: Agree
Comments
There are no comments.More in Mechanical Engineering:
Programming
Copyright ©CuriousTab. All rights reserved.