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

ANNA UNIVERSITY OF TECHNOLOGY, COIMBATORE

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. Why altemators are rated in kVA not in kW?

2. Why short pitch windings are preferred over full pitched winding?

3. What are the causes of changes in voltage of altemators when loaded?

4. What does hunting of synchronous motor mean?

5. Define slip of an induction motor.

6. What is induction generator?

7. Is it possible to add an external resistance in the rotor circuit of a cage induction motor? Justify your answer.

8. Mention the methods to change the speed of an induction motor.

9. Why the single‘phase induction motors are not self Starting one?

10. Mention the applications of stepper motor.

PART- B (5 X 16 = 80 MARKS)

11. a. Explain the construction and working principle of synchronous machines in detail (8)

b. The open circuit and short circuit test readings for a 3-phase star connected 1000 kVA, 2000V, 50 Hz synchronous generators are.....

EE52 Electrical Machines - II Fifth Semester Anna University of Technology, Tirunelveli, B.E EEE Nov Dec 2011 Question Paper

ANNA UNIVERSITY OF TECHNOLOGY, TIRUNELVELI

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

FIFTH SEMESTER - EEE

ELECTRICAL MACHINES 11

Time : Three hours MaXimum i 100 Marks

Answer ALL Questions

PART A - (10 X 2 = 20 Marks)

1. What do you mean by synchronous reactance?

2. What is the purpose of conducting slip test?

3. Is synchronous motor inherently self-starting or not.

4. State any two methods of starting synchronous motor.

5. What are the losses produced in induction motor?

6. Write down the equation for running torque of an induction motor.

7. Why induction motor draws large current from the supply during starting?

8. How many speeds you can obtain by cascaded connection of induction motors?

9. Why is the single phase induction motor having two winding in this stator?

10. State any two applications capacitor start run induction motor.

PART-B (5 X 16 = 80 MARKS)

11. a. 1) Explain the effects of armature reaction for different power factor loads. (8)

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

ANNA UNIVERSITY OF TECHNOLOGY, TRICHY

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. Define distribution factor.

2. What is damper winding? Why is it used?

3. Why does the synchronous motor develop torque only at synchronous speed?

4. What is a phase advancer?

5. Why three phase induction motor called singly excited motor?

6. Define slip.

7. How can speed of three phase induction motor be controlled?

8. What is induction generator?

9. Define step angle.

10. How will you change the direction of rotation of a split phase induction motor?

PART B - (5 x  16 = 80 MARKS)

11. a. Explain in detail MMF method of predetermining the voltage regulation of the alternator. (8)

b. A 4 -pole 3 phase, 50 Hz star connected alternator has 60 slots, with four conductors per slot. Coils are short pitched by three slots. If the phase spread is 60°, find the line induced voltage for a flux per pole of 0.943 Wb distributed sinusoidally in space. All the turns per phase are in series. (8)

or

12. a. Derive the expression for synchronizing current, power and torque. (10)

b, Calculate the maximum load on a 5 MVA, three phase alternator having a synchronous reactance of 5 ohm can deliver when connected to 6.6 kV bus bar if its excitation is such that the emf on open circuit is 6 kV. Find the armature current and power factor at this load. (6)

13. a. Derive an expression for power developed in a synchronous motor. (8)

b, A 3300 V, 1.5 MW, 3-phase Y connected synchronous motor has X d = 4 ohm per phase and Xq = 3 ohm per phase. Neglecting all losses, calculate the excitation EMF. When motor supplies rated load at unity PF. Calculate the maximum mechanical power would develop for this field excitation. (8)

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.

Anna University Chennai, EE52 Electrical Machines - II Fifth Semester B.E EEE May June 2011 Question Paper

Anna University Chennai

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

Regulations 2008

Fifth Semester - BEE

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)

ii. A motor generator set used for providing variable frequency a.c. supply consists of a three-phase, 10-pole synchronous motor and a 24-pole, three phase synchronous generator. The motor-generator set is fed from a 25 Hz three phase a.c. supply. A 6-pole, three phase induction motor is electrically

connected to the terminals of the synchronous generator and runs at a slip of 5%. Determine:

The frequency of the generated voltage of the synchronous generator.

The speed at Which the induction motor is running. (8)

Remaining questions can be collected from the images provided below.

Production Technology B.E Aeronautical 4th Sem Anna University 2011 Question Paper

Anna University old, model, previous and latest years question papers >> AE 2253 Production Technology, Fourth Semester B.E Aeronautical Engineering 2011 Question Paper: 

Are you searching for old, previous years and latest question papers of Anna University, Chennai ? You can find even sample and model question papers of Anna University and various universities in India. Have a look at this post which contains the latest year 2011 Anna University question paper conducted in the month April/May 2011, for the B.E/B.Tech Degree Examination 2011. This question paper is useful for those students who are preparing for Fourth Semester AE 2253 Production Technology for the course Aeronautical Engineering. Part A consists of 10 Questions and Part B has 5 questions of either or choice with a weight-age of 16 marks each. Use the question paper for your upcoming exams to score high marks.

Anna University, Chennai
B.E./B.Tech. Degree Examination, April/May 2011 
Aeronautical Engineering 
AE 2253 Production Technology 
Fourth Semester 
(Common to Third Semester Automobile Engineering)
(Regulation 2008)
Time : Three hours    
Maximum: 100 marks
Answer ALL questions
PART A (10 x 2 - 20 marks)

1.    List out the basic ingredients of moulding sand and their purpose.

2.    Define the term "green strength" and explain its importance in the context of moulding.

3.    Explain the term "weld-ability" and give two examples of weld-able metals/alloys.

4.    Give the advantages of resistance welding.

5.    What are the factors affecting machinability?

6.    Write the functions of dielectric fluid in EDM process.

7.    State the three types of compression moulding and their utilities.

8.    What are the two properties of polymer melts that are important in plastics processing?

9.    Define the term "Forgeabilily" and state the commonly used test for its assessment.

10.    Why do physical and mechanical properties depend on the density of P/M parts?

PART B (5 x 16 = 80 marks)

11.    (a) Explain in detail with neat sketches the various process steps in investment casting process giving the process details, process capabilities and their applications. (16)

Or

(b) Explain in detail with neat sketches life shell moulding and centrifugal casting process giving the process details, process capabilities and their applications. (16)


12.    (a) Describe in detail with neat sketch any two resistance welding processes, their advantages, disadvantages and applications. (16)

Or

(b) Describe in detail thermit welding and electron beam welding. Also list their applications. (8 + 8)

13.    (a) Explain with neat sketch the various parts of a lathe, method of specifying a lathe and any four types of lathe operations. (16)

Or

(b) Discuss in detail the USM process with respect to the following. (4 x 4 )

(i)    Description of the process

(ii)    Important process parameters and their relation to MRR

(iii)    Surface roughness obtained

(iv)    Electrode materials used.

14. (a) Explain in detail the injection moulding process with respect to the equipment and moulds used. Also discuss on the defects in injection moulding.       (16)

Or

(b) Describe in detail the compression and transfer moulding with neat sketches. (16)

15. (a) Explain the different types of extrusion process with sketches. Also list out the product applications of each process.:     (16)

Or

(b) Describe in detail on the production of metallic powders with respect to the following. (4 x 4)

(i)    Atomization

(ii)    Blending and mixing

(iii)    Compaction

(iv)    Sintering.

Anna University B.E Aeronautical Propulsion (AE2255) 4th Semester 2011 Question Paper

Anna University old, model, previous and latest years question papers >> AE2255 Propulsion, Fourth Semester (4th) B.E Aeronautical Engineering 2011 Question Paper: 

Want to get old, previous years and latest question papers of Anna University, Chennai ? You can find even sample and model question papers of Anna University and various universities in India. Have a look at this post which contains the latest year 2011 Anna University question paper conducted in the month April/May 2011, for the B.E/B.Tech Degree Examination. This question paper is useful for those students who are preparing for Fourth semester AE2255 Propulsion for the course Aeronautical Engineering. Part A consists of 10 Questions and Part B has 5 questions of either or choice with a weight-age of 16 marks each. Use the question paper for your upcoming exams to score high marks.

Anna University, Chennai
Question Paper Code : 11113
B.E./B.Tech. Degree Examination, April/May 2011 
Aeronautical Engineering 
AE2255 Propulsion
Fourth Semester 
(Regulation .2008)
Time : Three hours
Maximum: 100 marks
Use of gas tables permitted Answer ALL questions.
PART A (10 x 2 = 20 marks)

1. What are the advantages of closed cycle gas turbine cycle?
2. Water injection at inlet of a gas turbine engine increases thrust. Comment on the statement.
3. Draw T-S diagram for the inlet during low speed high thrust operation of a gas turbine engine.
4. Differentiate between subcritical arid Supercritical modes of inlet operation.
5. Define pattern factor. What is the desired range of this parameter?
6. What are the functions of dilution zone in combustion chamber of a gas turbine engine?
7. Define nozzle efficiency.
8. What is the need for variable area nozzle for supersonic operation?
9. What are the advantages of the axial flow compressor over the centrifugal flow compressor?
10. Define degree of reaction of an axial flow compressor.

PART B (5 x 16 = 80 marks)

11. (a) (i) Explain the working principle of Brayton cycle with regeneration. (6)

(ii)    In a gas-turbine plant working on Brayton cycle the air at the inlet is at 300 K, 0.1 MPa. The pressure ratio is 6.25 and the maximum temperature is 1073 K. The turbine and compressor efficiencies are each 80%. Find (1) compressor work per kg of air, (2) turbine work per kg of air and (3) turbine exhaust temperature.    (6)

(iii)  What is the effect of pressure ratio on the Brayton cycle efficiency?  (4)

Or

(b) (i) Draw a neat diagram of turbofan engine with axial flow compressor and explain its working principle.    (8)

(ii) What ii an afterburner and why is;it. used? Draw the T-S diagram of an ideal turbojet engine with an afterburner; explain the state points in the T-S diagram.    (8)

12. (a) (i) A jet plane travels through air with a speed of 285 m/s an altitude of 6000 m, where the pressure is 40 kPa,  the temperature is 261 K. The air leaves the diffuser of the engine of this airplane with a velocity of 100 m/s. Determine the pressure' and temperature of air leaving the diffuser, and the ratio of the inlet to exit area of the diffuser, assuming isentropic flow.    (8)

(ii) Performance wise highlight the requirements of a good inlet. Draw the streamline patterns along with T-S diagram for a subsonic inlet under varying speed operations.    (8)

Or

(b) (i) Discuss the effect of shock waves in supersonic inlets.

Schematically describe the working principle of internal compression and external compression type of supersonic inlets. (8),

(ii) An aircraft is flying at an altitude where the ambient static pressure is Po = 10 kPa and flight Mach number is Mo = 0.85. The total pressure at the engine face is measured to be P12  = 15.88 kPa . Assuming compression in the inlet is adiabatic and y = 1.4, calculate (1) the inlet total pressure recovery (2) the inlet adiabatic efficiency and (Ti) the non-dimensional entropy rise caused by the inlet.    (8)

13. (a) (i) Discuss the main factors of importance in assessing combustion chamber performances    (10)

(ii) Explain flame tube cooling of a gas turbine combustion chamber. (6)

Or

(b) (i) Discuss the classification of gas turbine combustion chambers.

Explain, with sketches.    (10)

(ii) Write down: any two methods of flame stabilization with sketches.

(6)

14. (a) (i) Plot Mach number, static temperature, static pressure and static density variations along the longitudinal axis of a convergent-divergent nozzle, when it flows full. Explain the variations.    (6)

(ii) A de Lavel nozzle has to be designed for an exit Mach number of 1.5 ; with exit diameter of 200 mm. Find the required ratio of throat area/exit area. The reservoir conditions are given as Po =10 bar, To =20 Deg C. Find also the maximum mass flow rate through the nozzle. What will be the exit pressure and temperature?   (10)

Or

(b) (i) Write short notes on the following :

(1) Variable area nozzle.    (4)

(2) Losses in nozzle. (4)

(ii) A converging-diverging nozzle operates at an atmospheric pressure of 68.95 KPa. It has a minimum area of 0.1393 m^2 and an exit area of 0.2786 m^2. The inlet total pressure, and temperature are 241.3 KPa and 611.1 K, respectively. The effective specific heat ratio is 1.34, and the nozzle efficiency is 98 percent. Find the exit velocity and mass flow rate.    (8)

15. (a) (i) What do you understand by degree of reaction in an axial flow compressor? Prove that degree of reaction A in an axial flow compressor is given by

A = (tan B1 - tan B2)Ca / 2U    (8)           [ Note: Read B as Beta]

(ii) Draw a neat diagram of axial flow compressor and explain functions of all parts and its working principle    (8)

Or :

(b) (i) A sixteen-stage axial flow compressor is to have a pressure ratio of 6.3. Tests have shown that a stage total-to-total efficiency of 0.9 can be obtained for each of the first six stages and 0.89 for each of the remaining ton stages. Assuming constant work done in each stage and similar stages find the compressor overall total-to-total efficiency. For a mass flow rate of 40 kg/s determine the power required by the compressor. Assume an inlet total temperature of 288 K                            (8)

(ii) Discuss the factors affecting stage pressure rise of an axial flow compressor with suitable sketches.    (8)