SRM University 2007 B.Tech Electronics and Communications Engineering BANK - Question Paper

10. Explain ward leovard system of speed control of DC shunt motor
11. State DC motor principle and compare the generator and motor action.
12. What is back EMF? discuss its significance and derive the voltage formula of the Dc motor and the max –condition for power developed in a DC motor.
13. Define the different torque developed in a motor and, derive the expression for the identical.
14. Explain the different ways by which speed of an DC motor can be controlled.
15. Enumerate on the characteristic of shunt motors.
16. Elaborate on the characteristics of series motors.
17. Draw the power stages diagram of a DC motor and derive the expression for mechanical, overall, and electrical efficiency from the different losses of the DC motor
18. Write a detailed note on starters of DC motors by discuss the need of a starter.
19. Write a note on starters of series motors.
20. Write a note on Thyristor controlled starters.

UNIT – II

21. State the working principle of a transformer. discuss the construction of the identical.
22. Write a detailed note on elementary theory of an Ideal transformer with necessary vector diagram.
23. Derive EMF formula of a transformer.
24. Write a note on transformer, When it is subjected to 3 various loads with necessary circuit diagram.
25. Derive the equivalent circuit of a transformer.
26. Write a note on DC & SC test on transformer.
27. Define regulation of a transformer and derive an expression on up & down regulation of a transformer
28. Explain the different losses in a transformer. How can it be minimized? State the condition for max?
29. State the working principle of IM and discuss the construction.
30. How 2F rotating may field is produced in a IM?
31. How 3F rotating may field is produced in a IM?
32. How will you control the speed of an Induction motor from stator side
33. How will you control the speed and the IM from rotor side
34. Derive expression for starting torque & running torque.
35. Write a detailed account on starters of Induction Motors.
36. Explain the torque – slip characteristics of IM
37. A 25KVA transformer has 500turns on the primary and 50turns on the secondary winding. The primary is connected to 3000V, 50Hz supply. obtain the full load primary and secondary currents, the secondary emf and the maximum flux in the core. Neglect leakage drops and no load primary current.
38. A 1F transformer with a ratio of 440/110V takes a no-load current of 5A at 0.2pf lagging. If the secondary supplies a current of 120A at a pf of 0.8 lagging, estimate the current taken by primary.

UNIT - III

39. Explain in detail about the concept of double field revolving theory.
40. Single phase induction motor is not a self starting motor why? discuss the cause. Write all the available methods to make the motor as a self starting one.
41. With neat diagram discuss the construction and working of 1F induction motor.
42. Explain in detail about all the kinds of capacitor begin motor.
43. With neat diagram discuss all the kinds of capacitor begin run motor. State the disadvantages of it.
44. Explain the speed torque characteristics of capacitor start-run motor. discuss split phase motor.
45. Explain the phasor diagram of split phase, capacitor start-run induction motor.
46. Deduce the equivalent circuit of 1F induction motor with and without core loss.
47. Explain in detail about the construction and working of an universal motor.
48. Explain the construction and working of stepper motor. Call the kinds.
49. Explain the construction and working of servo motor.
50. Compare variable reactance motor and hybrid stepper motor.

UNIT - IV

51. What is the basic constructional difference ranging from ac generator and dc generator? Which is advantageous? Why?
52. With a neat diagram discuss the construction and working of an alternator?
53. Explain the effect of armature reaction in an alternator.
54. Draw and discuss the phasor diagram of an alternator for varying load conditions.
55. Explain the construction and working of a synchronous motor.



UNIT – V

56. Explain about the 3 stages in electric supply system.
57. Explain the various systems of wiring.
58. Explain the various kinds of earthing.
59. Explain in detail about electric supply system with 3F – 4wire distribution system.
60. Explain in detail about the general requirement for earthing.
61. Draw the wiring diagram for home electric wiring.
62. Write short notes on protection of electric installation against
(i) Overload
(ii) Short circuit
(iii) Earth Faust
63. Write short notes on (i) Fuses (ii) Circuit breakers
64. Explain in detail about protection against electric shock.
65. What are the general requirements for electrical installations?
66. Explain in detail about service connections.
67. Explain in detail about service mains.
68. Explain in detail about location of main board and distribution board with neat diagram.
69. Draw the wiring diagram for factory and discuss in detail.
70. Draw the wiring diagram for Industry and discuss in detail.

Earning:   Approval pending.