Question Paper of Anna University Chennai, EE52 Electrical Machines - II Fifth Semester B.E EEE November December 2011

ANNA UNIVERSITY

B.E./B.TECH. DEGREE EXAMINATION, November/December 2011

FIFTH SEMESTER : EEE

ELECTRICAL MACHINES II

Time : Three hours       Maximum : 100 Marks

 Answer ALL Questions

PART A - (10 X 2 = 20 Marks)

1. What do you mean by single layer and double layer winding?

2. What are the various function of damper winding provided with alternator?

3 What is a synchronous capacitor?

4. What are V-curves?

5. What are the rotor slots of a 3-phase induction, motors skewed?

6. Define slip of induction motor.

7. State the effect of rotor resistance on starting torque. 

8. What are the various method of speed control of 3-phase induction motor

9. What type .of motor is used for ceiling fan?

10. State the application of shaded pole motor.

PART B (5 X 16 = 80 MARKS)

11. a. i) Derive from first principle, the emf of 3-phase alternator. (8)

ii) The following open circuit and short circuit test are made on a 6000 kVA, 6600 V, star connected, 2-pole; 60 Hz turbine driven alternator. If I = 125 A, at open circuit terminal voltage = 8200 V with armature short circuited I = 125 A (line). At the rated load and upf armature loss is 1.5%.of output.

Determine the percentage regulation at rated load and 0.8 p.f. lag. (8)

or

b. 1) Explain how will you determine the d and q-axis reactance of a synchronous machine in your laboratory. (3)

ii) For the salient synchronous machine, derive the expression for power developed as a function of load angle. (3)

B.E/B.Tech Degree Examinations May / June 2011 Anna University EE52 Electrical Machines - II Question Paper

B.E/B.Tech Degree Examinations May / June 2011

Regulations 2008

Fifth Semester - EEE

EE52 Electrical Machines - II

Electrical and Electronics Engineering

Time : 3 hours  Max. Marks : 100

Part-A (10 x 2 = 20 marks)

Answer all Questions

1. What are the effects of Armature reactor?

2. State the condition for parallel operations of Alternator.

3. List any two characteristic features of synchronous motor.

4. What is the synchronous condenser?

5. Why is the Induction motor always runs with the speed less than the synchronous speed?

6. Define slip.

7. What is the need for starters in Induction motor?

8. What are the speed control techniques applicable to squirrel cage induction motor?

9. Define double field revolving theory.

10. Write down any two applications of single phase induction motors

.

Part-B (5 x 16 = 80)

11. a) i. Derive the emf equation of Alternator. (8)

Question Paper of Anna University of Technology Coimbatore, EE52 Electrical Machines - II Fifth Semester B.E EEE April May 2011

ANNA UNIVERSITY OF TECHNOLOGY, COIMBATORE

B.E./B.TECH. DEGREE EXAMINATION, April/May 2011

FIFTH SEMESTER - EEE

ELECTRICAL MACHINES II

Time : Three hours  Maximum : 100 Marks

Answer ALL Questions

PART A - (20 X 2 = 40 Marks)

1. Name the main parts of synchronous generator.

2. Write down the EMF equation of alternator.

3. Define regulation of alternator. '

4., Name the different methods of determining the voltage regulation of synchronous generator.

5. Synchronous motor always runs at synchronous speed why?

6. What is hunting?

7. What are V-curves?

8. What are the uses of damper winding in a synchronous motor?

9. How will you change the direction of rotation of three phase induction motor?

10. What is Slip?

11. List the application of slip ring induction motor?

12. Why an induction motor is called asynchronous motor?

13. What is the disadvantages of dynamic braking of an induction motor?

14. What is eddy current loss?

15. How does the slip vary with load?

16. Is it possible to start 3-phase slip ring induction motor on load?

17. What kind of motor is used in a mixie?

18. In which direction does a shaded pole induction motor run?

19. Why single phase induction motor has low power factor?

20. .What do you mean by split phase motor?

PART B (5 x 12 =  60 Marks)

Answer any five questions

21. Explain the double field revolving theory for Operation Of Single Phase induction motor.

22. Explain the principles of operation and applications of repulsion motor and hysteresis motor.

Question Paper of Anna University of Technology, Coimbatore, 080280039 Electrical Machines - II Fifth Semester B.E EEE Nov Dec 2010

Anna University of Technology, Coimbatore

B.E/B.Tech Degree Examinations Nov/Dec 2010

Regulations 2008

Fifth Semester - EEE

080280039 '- Electrical Machines - II

Time : 3 hours - Max. Marks : 100

Part - A (20 x 2 = 40 marks)

Answer all Questions

1. What are the conditions to be satisfied for the proper synchronization of alternators?

2. Write down the equation for frequency of emf induced in an alternator.

3. What is meant by synchronous impedance of an alternator?

4. Define the term voltage regulation of an alternator.

5. How a DC generator. can be converted in to an alternator?

6. Mention different power stages in a synchronous motor.

7. Write the various torques associated with a synchronous motor.

8. What is hunting? 

9. Write the applications of synchronous motor.

ll). Mention the advantages of skewed rotor slots?

11. Define the term slip.

12. List the available methods for measurement of slip of an induction motor?

13. List the different methods of which speed control of induction motor is achieved.

14. What is crawling?

15. What could be reasons for very slow running of split phase motor?

16. Mention the two types of unexcited single-phase synchronous motor? 

17. A slip-ring induction motor runs at 290 rpm at full load when connected to 50 HZ supply. Determine the number of poles and slip. Assume Ns = 300 rpm.

18, How would you reverse the direction of rotation of a capacitor start-induction run motor?

19. Define the term step angle in stepper motor.

20. Mention the application of switched reluctance motor.

Part B carrying 60 marks in total, will be available in the following images. Download the images and share it with friends.

Anna University of Technology, Tirunelveli, EE52 Electrical Machines - II Fifth Semester B.E EEE Nov Dec 2010 Question Paper

Anna University of Technology, Tirunelveli

B.E/B.Tech Degree Examinations Nov/Dec 2010

Fifth Semester

Electrical and Electronics Engineering

EE 52 - Electrical Machines - II

(Regulations 2008)

Time :3 hours - Max.marks : 100

I Answer all Questions

Part - A (10 x 2 = 20 marks)

1, Define the voltage regulation.

2, What is synchronizing torque?

3. Why synchronous motor is not self starting?

4. ' Draw the power angle curve of synchronous motor.

5. . Mention the advantages of double gauge induction motor.

6. List the various factors governing the starting torque of an induction motor.

7. What is the effect of increase in rotor resistance on starting torque of slip ring induction motor?

8. Draw the slip and torque characteristics of slip ring induction motor.

9. State the applications of induction generator. I

10. Mention the working principle of hysteresis motor.

More questions on part B can be had at the following images