Steam Nozzles and Turbines problems
- 1. The impulse turbine rotor efficiency will have a maximum value of 0.5 cos2 ?, where ? is the nozzle exit flow angle, if the
Options- A. blades are equiangular
- B. blade velocity coefficient is unity
- C. blades are equiangular and frictionless
- D. blade solidity is 0.65 Discuss
Correct Answer: blades are equiangular and frictionless
- 2. The density of supersaturated steam is about __________ that of the ordinary saturated vapour at the corresponding pressure.
Options- A. same as
- B. 2 times
- C. 4 times
- D. 8 times Discuss
Correct Answer: 8 times
- 3. The flow of steam is super-sonic
Options- A. at the entrance to the nozzle
- B. at the throat of the nozzle
- C. in the convergent portion of the nozzle
- D. in the divergent portion of the nozzle Discuss
Correct Answer: in the divergent portion of the nozzle
- 4. Curtis turbine is a
Options- A. simple reaction turbine
- B. velocity compounded turbine
- C. pressure compounded turbine
- D. pressure-velocity compounded turbine Discuss
Correct Answer: pressure-velocity compounded turbine
- 5. The diagram efficiency is the ratio of
Options- A. workdone on the blades to the energy supplied to the blades
- B. workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
- C. energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
- D. none of the above Discuss
Correct Answer: workdone on the blades to the energy supplied to the blades
- 6. The velocity of steam, in reaction turbines, is increased in the fixed blades as well as in moving blades.
Options- A. True
- B. False Discuss
Correct Answer: True
- 7. In order to reduce the rotor speed of an impulse turbine, the method employed is
Options- A. velocity compounding
- B. pressure compounding
- C. pressure-velocity compounding
- D. all of these Discuss
Correct Answer: all of these
- 8. De-Laval turbines are mostly used
Options- A. where low speeds are required
- B. for small power purposes and low speeds
- C. for large power purposes
- D. for small power purposes and high speeds Discuss
Correct Answer: for small power purposes and high speeds
- 9. Blading efficiency is also known as
Options- A. stage efficiency
- B. diagram efficiency
- C. nozzle efficiency
- D. none of these Discuss
Correct Answer: diagram efficiency
- 10. The Rankine efficiency depends upon total useful heat drop and total isentropic heat drop.
Options- A. Correct
- B. Incorrect Discuss
Correct Answer: Incorrect
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