Anna University - Electrical Engineering - Question Bank

Anna University - Question Bank

UNIT – I

PART – A

1. Define electric motor.
2. Define electric generator.
3. Define excitation.
4. What are the methods of excitation?
5. What do you mean by self excited machine?
6. What do you mean by separately excited machine?
7. State the function of commutator.
8. What do you mean by commutation?
9. What is the purpose of brushes?
10. By which material yoke can be manufactured?
11. Why the brushes are made upon carbon?
12. What are the types of self excited generator?
13. Define shunt generator.
14. Define series generator.
15. Define compound generator.
16. Draw the open circuit characteristics of dc separately excited generator.
17. What do you mean by magnetization curve?
18. Draw the load characteristics of separately excited dc generator.
19. Draw the characteristics for DC shunt generator.
20. Draw the characteristics of DC series generator.
21. Draw the characteristics of DC compound generator.
22. What is the principle of operation of dc generator?
23. Write down faradey's law of electromagnetic induction.
24. What is the principle of operation of DC motor?
25. State lenz's law.
26. How Lenz's law is helpful for the operation of DC motor?
27. Write the significance of back e.m.f.
28. Define back e.m.f.
29. Write the e.m.f. equation of DC generator.
30. Write down the voltage equation of DC motor.
31. Write the torque equation of DC motor.
32. Draw the characteristics of DC shunt motor.
33. Draw the characteristics of DC series motor.
34. Draw the characteristics of DC compound motor.
35. Differentiate differentially compound and cumulatively compound motor.
36. What are the applications of DC shunt motor?
37. What are the applications of DC series motor?
38. What are the applications of DC compound motor?
39. Why shunt motor is called as constant speed machine?
40. Why starter is needed in DC motor?
41. What is the advantage of 4 point starter over 3 point starter?
42. State the function of no volt coil.
43. State the function of over load release.
44. What is the advantage of conducting Swin-burne's test?
45. Draw the diagram of ward-leanord system of speed control.
46. By which method, we can control the speed of the motor below the base speed?
47. By which method, the speed control of the DC motor be above the base speed?
48. What are the various methods of speed control of DC motor?
49. Differentiate armature voltage control method and field flux control method.
50. What do you mean by brake test?

PART – B

51. Explain in detail the constructional details of DC machine.
52. Derive the e.m.f. equation (8)
53. Draw and explain the characteristics of DC generator.
54. Derive the torque equation/
55. Write down the significance of back e.m.f.
56. Write down the principle of operation of DC motor.
57. Draw and explain the characteristics of DC motor.
58. Draw and explain 3 point starter.
59. What is the draw back in 3 point starter and how it is overcome in 4 point starter?
60. Explains the procedure of swin burne's test.
61. Draw and explain the speed control methods of DC shunt motor.
62. Explain in detail about the ward-leonard system of speed control of DC motor.
63. Problem.

UNIT – II

PART – A 

1. State the principle of operation of transformer.
2. What are the types of transformer according to its construction?
3. Differentiate core type transformer and shell type transformer.
4. Write down the e.m.f equation of transformer.
5. Write down the transformation ratio.
6. Define magneting current component.
7. Define working current component.
8. Draw the vector diagram of transformer an no load.
9. How the resistance of the secondary be referred in the primary?
10. Draw the approximate equivalent circuit of the transformer.
11. Draw the vector diagram for the transformer under resistive load.
12. Draw the vector diagram for the transformer under inductive load.
13. Draw the vector diagram of the transformer under comparative load.
14. When the transformer is said to be ideal?
15. Define voltage regulation of transformer.
16. Define voltage regulation up.
17. Define voltage regulation down.
18. By conducting no load test, which losses can be found out?
19. Which losses can be found out by conducting short circuit test?
20. What are the tests to be conducted on the transformer?

PART - B

1. Derive the e.m.f. equation of transformer.
2. Explain in detail about the transformer on no load.
3. Draw and explain ideal transformer. Draw its vector diagram.
4. Obtain the equivalent circuit of the transformer by conducting suitable tests.
5. Draw and explain in detail about the transformer an load.
6. Derive the regulation formula for the transformer.
7. Explain in detail about the testing procedures for the transformer.
8. Problem.

UNIT – III

PART – A 

1. Write the working principle of induction motor.
2. How RMF is produced with the help of 3 phase supply?
3. Define slip.
4. Write the working principle of 3f induction motor.
5. Why 3f induction motor is called as rotating transformer?
6. Can the rotor speed of induction motor be synchronous speed?
7. What are the types of induction motor?
8. Write down the torque equation of 3f induction motor.
9. Draw the slip-torque characteristics.
10. Draw the speed-torque characteristics.
11. State the relation between P₂, P_c and P_m.
12. Draw the Power flow diagram of 3 phase induction motor.
13. Draw the equivalent circuit of 3 f induction motor.
14. Why starter is necessary in AC induction motor?    
15. What are the types of starters available to start 3 f induction motor?
16. Why single phase induction motor is not self starting?
17. How single phase induction motor is made to start?
18. How the rotor is classified in 3f induction motor?
19. How Rmf is produced in the stator of the induction motor
20. What is Rmf?

PART - B

1. Explain the constructional details of 3 f induction motor.

2. How Rmf is produced with the help of 3 f AC supply?

3. Explain in detail the principle of operations of 3 phase induction motor.

4. Explain the procedure to obtain the equivalent circuit of 3 phase induction motor.

5. Derive the torque equation of 3 phase induction motor.

6. Draw and explain the characteristics of 3 phase induction motor.

7. Explain in detail about (i) Star-delta starter (ii) Auto transformer starter (iii) DOL starter.

8. Write short notes on single phase transformer.

9. Why single phase induction motor is not self starting? Explain the methods available to start the motor.

10. Write short notes on speed control of 3 f induction motor.

UNIT IV

PART – A 

1. What are the types of synchronous machines?
2. What is the basic principle of operation 3f alternator?
3. Why stationary armature is there in 3f alternator?
4. Write down the e.m.f. equation of alternator.
5. What are the types of 3 f alternator?
6. Define voltage regulation of alternator?
7. What are the methods to find out voltage regulation?
8. Why synchronous impedance methods is called as pessimistic method?
9. What are the methods to find out voltage regulation
10. Why synchronous impedance method is called as pessimistic method?
11. Define synchronous impedance.
12. Why ampere-turns method is called as optimistic method?
13. Draw the phasor diagram for voltage regulation in synchronous impedance method.
14. How emf is induced in brushless alternator?
15. What is the function of rotating diode assembly in brush can alternator?
16. What do you mean by brushless excitation?
17. How reluctance motor is running?
18. What is the operating principle of hysteresis motor?
19. What are the types of stepper motor?
20. How do you find step angle in stepper motor?
21. Give the application of stepper motor.

PART - B

22. Derive the emf equation of alternator.
23. Write down the procedure of finding voltage regulation of alternator using synchronous impedance method.
24. Write down the procedure for finding voltage regulation using ampere-turns method.
25. Explain in detail the construction of synchronous machine.
26. Write short notes on (i) Brushless alternator (ii) Reluctance motor (iii) Hysteresis motor (iv) Stepper motor.

UNIT – V

PART – A

1. What are the various sources of electric power generating system?
2. What is the purpose of step up transformer in electrical power system?
3. What do you mean by carona loss?
4. What is meant by Ferranti effect?
5. What are the advantages of AC transmission?
6. What are the advantages of DC transmission?
7. What are the types of distribution system?
8. What is EHUAC?
9. Define EHUDC.
10. What is the purpose of circuit breakers.
11. Define insulators.
12. Why the transmission is done through under ground cable?
13. What are the advantages of under ground cables?
14. What are the types of under ground cables?
15. What are types of insulators?
16. What is pin insulator? Where it is used?
17. What is stay insulator? Where it is used?
18. What are the purposes of insulator?
19. Define service mains.
20. Define grid.
21. Differentiate feeders and distributors.

PART - B

1. Explain in detail, the single line diagram of electrical power system.
2. Explain in detail the various types of transmission and distribution systems.
3. Distinguish EHUAC and EHUDC systems.
4. Explain in detail the substation lay out.
5. Write short notes as (i) Insulators (ii) cables.