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Questions (50 - 56)
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In this lesson, questions ( 50 - 56) have been discussed.

Harshit Aggarwal
Cleared UPSC ESE twice with Rank 63 and 90 in mechanical engg. Got 99 percentile in GATE. Cracked ONGC, BHEL,ISRO, SAIL, GAIL successfully

Unacademy user
  1. COURSE: Questions on Steam Turbine Lesson : Questions-(50- 56

  2. About me Graduated from NIT Nagpur in 2008 A. Cleared Engineering Services Examination (ESE-UPSC) Exam Got the offer letter from most of the Maharatna and Navratna Companies Cleared GATE Exam Rate, Review, Recommend, Share <* Follow me on Unacademy at: aggarwal

  3. Question 50 Which one of the following expresses the maximum blade efficiency of a Parson's turbine? 2 cos2 1+cos2 cos2 1+2cos" cos coS o 1+cos2 Where a is the jet angle at the entrance Ans a

  4. Question 51 What is the value of the reheat factor in multi-stage turbine? (a) 1.03 to 1.04 (b) 1.10 to 1.20(c) 0.90 to 1.00 (d) 1.20 to 1.25 Ans: a

  5. Question 52 Which one of the following statements is correct? (a) Reheat factor is zero if efficiency of the turbine is goes to unity (b) Lower the efficiency, higher will be the reheat factor. (c) Reheat factor is independent of steam conditions at turbine inlet (d) Availability of reheat is higher at low pressure end. Ans: b

  6. Question 53 Which one of the following pairs is NOT correctly matched? (a) Internal efficiency of steam turbine: Product of stage efficiency and reheat factor (b) Stage efficiency of a turbine: Ratio of adiabatic heat drop to the isentropic heat drop per stage (c) Dryness fraction of steam within a stage: Decreases due to reheating (d) Steam condensation during expansion: Enhances blade erosion through the turbine Ans c

  7. Question 54 Which one of the following pairs is correctly matched? (a) Stage efficiency -actual enthalpy drop (b) Nozzle efficiency (c) Diagram efficienc;y (d) Blade efficiency - workdone on moving blades isentropic enthalpy drop work delivered isentropic enthalpy drop - Work deliveredby blades isentropic enthalpy drop actual enthalpy drop Ans a

  8. Question 55 Given, ,-stage efficiency ,-nozzle efficiency ,-blade efficiency Which one of the following is correct? Ans : d

  9. Question 56 Assertion (A): In the case of reaction turbines for power plant applications, a large number of stages is common in practice. Reason (R): A pressure drop takes place in the moving blade in a reaction turbine unlike an impulse turbine, where pressure remains constant across the moving blade (a) Both A and R are individually true and R is the correct explanation of A (b) Both A and R are individually true but R is not the correct explanation of A (c) A is true but R is false (d) A is false but R is true Ans b