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Questions (36 - 42)
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In this lesson, questions (36 - 42) 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
Priyanka Aggarwal
3 months ago
Good Vipin ji 😊👍 keep doing
i cant understand question no. 40 please sir give some detail explanation
q 38 option c in made easy book is correct answer plz rpy sir
  1. COURSE: Questions on Steam Turbine Lesson : Questions -(36-42)


  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: https://unacademy.in/user/harshit aggarwal


  3. Question 36 In a reaction turbine stage enthalpy drop in the stator blades is 4.62 kJ/kg and that in the rotor blades is 2.38 kJ/kg. The degree of reaction of the stage is (a) 0.52 (b) 0.43 (c) 0.34 (d) 0.26


  4. Solution 36 degree of reaction2mb (Ah)^h) 2.38+4.62 Ans c


  5. Question 37 Assertion (A): Parsons turbine has a degree of reaction equal to 50%. Reason (R): It is a reaction turbine with symmetrical fixed and moving blades (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 a


  6. Question 38 The degree of reaction of a turbine is defined as the ratio of (a) Static pressure drop to total energy transfer (b) Total energy transfer to static pressure drop (c) Change of velocity energy across the turbine to the total energy transfer (d) Velocity energy to pressure energy Ans a


  7. Question 39 The following data refer to an axial flow turbine stage: Relative velocity of steam at inlet to the rotor- 79.0 m/s., Relative velocity at the rotor exit- 152 m/s rotor mean peripheral velocity 68.4 m/s, work output per kg of steam = 14100 J. What is the approximate degree of reaction? (a) 0.9 (b) 0.8 (c) 0.7 (d) 0.6


  8. Solution 39 152-7 Enthalpy drop in moi blades 2x1000 20008.43kl/kg Enthalpy drop in moving blades Degree of Reaction0.597 0.6 14.1 Ans d


  9. Question 40 The isentropic enthalpy drop in moving blade is two-thirds of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be (a) 0.4 (b) 0.6 (c) 0.66 (d) 1.66


  10. Solution 40 Ah (moving blade) Ah (moving blade)+Ah(fixed blade) 0.4 Degre of reaction - Ah (moving blade)-Ahf(fixcd blade) Ans a


  11. Question 42 Assertion (A): Reaction turbines are not built on pure reaction principle. Reason (R): Pure reaction is difficult to realise in practice. (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 a