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- Question
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
- Correct Answer
- True
- 1. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ number of stages are required.
Options- A. more
- B. less Discuss
- 2. De-Laval turbine is a
Options- A. simple impulse turbine
- B. simple reaction turbine
- C. impulse-reaction turbine
- D. none of these Discuss
- 3. 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
- 4. The effect of friction on the flow of steam through a nozzle is to
Options- A. decrease the mass flow rate and to increase the wetness of steam
- B. increase the mass flow rate and to increase the exit temperature
- C. decrease the mass flow rate and to decrease the wetness of steam
- D. increase the exit temperature without any effect on mass flow rate Discuss
- 5. For maximum efficiency of an impulse turbine, the steam should leave the blades at right angles to their motion.
Options- A. Correct
- B. Incorrect Discuss
- 6. 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
- 7. 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
- 8. 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
- 9. 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
- 10. 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
Steam Nozzles and Turbines problems
Search Results
Correct Answer: less
Correct Answer: simple impulse turbine
Correct Answer: all of these
Correct Answer: decrease the mass flow rate and to decrease the wetness of steam
Correct Answer: Correct
Correct Answer: superheated steam
Correct Answer: 640/3 m/s
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
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