Thermodynamics Part-III (Turbines & Pumps)

Mechanical One liner Subjective Questions - Answers for Quick Revision and Competitive Exams. 

THERMODYNAMICS - PUMPS AND TURBINES

In this post we are sharing the Engineerring Thermodynamics -Heat & Mass one liner subjective questions answers notes. This subject contains short notes topic wise. This book is very useful for your semester as well as for competitive exams.

1. The undershot water wheels are those in which – The wheel runs entirely by the Impulse of water
2. Breaking jet in an impulse turbine used to – Bring the runner to rest in short time
3. A reciprocating pump – requires air vessel.
4. A Pelton wheel is – tangential flow impulse turbine
5. An impulse turbine used for – high head of water
6. The hydraulic efficiency of an impulse turbine is the – ratio of the work done on the wheel to the energy of the jet.
7. The mechanical efficiency of an impulse turbine is the – ratio of the actual work available at the turbine to the energy imparted to the wheel
8. The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is one of the jet velocity – one-half
9. He maximum hydraulic efficiency of an impulse turbine is – (1 + cos)/2
10. The overall efficiency of pelton  wheels lies between – 0.85 to 0.90
11. Double overhung pelton wheel has – two runners
12. The width of the  bucket for a Pelton wheel is generally the diameter of jet – 5 times
13. The depth of the bucket for a pelton wheel is generally the diameter of- 1.2 times
14. Jet ratio is defined as the ratio of the – diameter of pelton wheel to the diameter of jet
15. The number of packets on the Periphery of a pelton wheel is given by- D/2d+15
16. In an inward flow reaction turbine – the water enters the wheel at the outer Periphery and then flow towards the centre of the wheel
17. Overall efficiency of a reaction turbine is the ratio of – power produced by the turbine to the energy actually supplied by the turbine
18. The Runaway speed of hydraulic turbine is the speed – at which the turbine will run freely without load
19. The power developed by turbine is – directly proportional to H
20. The unit power developed by turbine is – P/H
21. The speed of turbine runner is directly proportional to – H
22. The unit of speed of the turbine runner is – N/H
23. The unit discharge through the turbine is – Q/H
24. The specific speed of turbine is given by the equation – NP
25. Which of the following turbine is preferred 40 to 25 m head of water –  Kaplan turbine
26. Which of the following turbine is preferred for a specific speed of 60 to 300 r.p.m – Francis turbine
27. For 450 m head of water shall be used – Pelton wheel
28. A Pelton wheel working under a constant head and discharge has maximum efficiency when the speed ratio is – 0.46
29. The Cavitation in a hydraulic machine is mainly due to – low pressure
30. Multi-stage centrifugal pumps are used to produce – high heads
31. Slip of reciprocating pump is defined as – the difference of theoretical discharge and the actual discharge
32. In a reciprocating pump air vessels are used to – reduce acceleration head
33. Discharge of centrifugal pump is – directly proportional to N
34. Delivery head of centrifugal pump is directly proportional to N
35. For centrifugal pump  pump impeller the maximum value of the vane exit angle is 20 to 25 degree
36. Which of the following is successfully used for lifting water from deep wells – air lift pump
37. Which of the following is successfully used for lifting water to the turbine – Jet pumps
38. Centrifugal pumps operating in series will result in – higher head 

More :- 

• Thermodynamics Part-I (Energy Conversion) 
• Thermodynamics Part-II (Heat and Mass)

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