Anna University
Department of Electrical and Electronics Engineering
Fifth Semester
EE2305 Electrical Machines II
VIVA Questions
(Regulation 2008)
1. What is regulation of a transformer?
2. What are the different losses in a transformer?
3. What are the different types of transformers?
4. What is the efficiency of a transformer when compared with Induction motor?
5. What is the working principle of transformer?
6. What happens when DC is given to primary of a transformer?
7. Why the transformers are rated in KVA?
8. What is the working principle of 3 – phase induction motor?
9. What are the different types of 3 – phase induction motor?
10. As the load increases, what happens to the speed of the motor?
11. Why 3 – phase induction motor is widely used for industrial applications?
12. What are the various losses in induction motors?
13 Why induction motor is called as rotating transformer?
14. What is the working principle of alternator?
15 .Give the difference between A.C. Generator and D.C Generator.
16. Why alternators are rated in KVA?
17.What are advantages of stationary armature?
18.Is the efficiency of the alternator is determined by direct loading?
19.Give the e.m.f equation of an Alternator
20. what should be the rating of two transformers for parallel operation
21. what is the advantage of parallel operation of transformers
23. with the help of parallel operation can we calculate the efficiency
24. What are the different losses in a transformer
25. If the regulation is less then the transformer is a good transformer or not
26. Define regulation of a transformer
27. what is the effect on losses of a transformer with variation supply frequency
28. What is a teaser transformer?
29. What are the advantages of Scott Connection?
30. What do you mean by Tertiary Winding?
31. What is the percentage of winding at which Scott connection is made?
32. What are the applications of Scott Connection?
33. What is meant by Quadrature and Direct axis reactance?
34. What is meant by two axis reactance theory
35. What is the relation between Xd &Xq for non salient pole machine
35. Why this test is called as Slip test
36. What are the advantages of Slip Test?
37. Which type of power plants Salient pole Alternators are used.
38. What is the other name for sumpner’s test?
39. What are the advantages of Sumpner’s test when compared with the other tests?
40. Define regulation of a transformer
41. What are the disadvantages of Sumpners Test?
42. Sumpener’s test is a direct test or indirect test
43.Define regulation of an alternator
44.Why emf method is called as pessimistic metrhod
45.What is the disadvantage of emf method
46.What is meant by synchronous impedance
47.Is synchronous impedance constant with respect to Excitation
48.What is the other name for mmf method
49. State the conditions, under which no-load test is performed?
50. Which theory is commonly used for the analysis of induction motor?
51. What is the slip of forward and backward rotors?
52. What is the phase displacement in space between the two windings?
53. How the phase splitting can be increased between the two windings?
54. How is the starting winding disconnected from the supply?
55. What is the torque line in the Circle Diagram?
56. In comparison with transformer Induction motor is having high efficiency or low
efficiency
57. What are the advantages of circle diagram?
58. What is the assumption made for drawing a circle diagram?
59. Is SC and OC test is Possible for both type of Induction motors
60. What are the different starting methods of a 3 phase induction motor?
61. What is the value of slip for an induction generator?
61. What is the principle operation of a Synchronous Motor?
62. What is the application of Synchronous Motor?
63. What is advantage of plotting the V & Λ Curves
64. What is Load Angle?
65. The active component of armature current is having const magnitude or varies
66. What happens to the pf if the field current is gradually increased