23053 - SPECIAL ELECTRICAL MACHINES - IMPORTANT QUESTIONS

DIPLOMA IN ELECTRICAL AND ELECTRONICS ENGINEERING

SUBJECT CODE      : 23053

SEMESTER               : V SEMESTER

SUBJECT TITLE      : SPECIAL ELECTRICAL MACHINES

STAFF-IN-CHARGE: N.SURESH KUMAR

IMPORTANT QUESTIONS

UNIT-I

PART-A

1.     State Any Two Properties Of Synchronous Reluctance Motors-Oct 2013

2.     Write Down Torque Equation Of PMSM-Oct 2013

3.     List Any One Application Of SyRM-Oct 2013

4.     Give EMF Equation Of PMSM-Oct 2013

5.     Write down the torque of permanent magnet synchronous motor.-April 2014

6.     How electronic circuit control the proper operation of permanent magnet synchronous motor. -April 2014

7.     Write any two application of PMSM. -April 2014

8.     Write one disadvantage of synchronous reluctance motor. -April 2014

9.     State the difference between permanent magnet motor and pure reluctance motor?

10.            What type of supply is given for permanent magnet synchronous motor?

11.            Give the EMF equation of permanent magnet synchronous motor.

12.            Mention any two advantages of pure reluctance motor.

PART-B

1.     Derive From The First Principles The EMF Equation Of PMSM (12) -Oct 2013

2.     Explain How Static Torque Is Produced In SyRM(12) -Oct 2013

3.     Draw and explain the speed torque characteristics of permanent magnet synchronous motor. (12) -April 2014

4.     Explain the construction and operation of synchronous motor. (12) -April 2014

5.     With neat sketch explain the constructional features and operating principle of permanent magnet synchronous reluctance motor.(12)

6.     Draw and explain the phasor diagram of permanent magnet synchronous motor. (12)

UNIT-II

PART-A

1.     What Is The Principle Of SRM? -Oct 2013

2.     List Any Two Applications Of SRM-Oct 2013

3.     Mention Any Two Drawbacks Of SRM-Oct 2013

4.     Draw Torque-Speed Characteristics Of SRM-Oct 2013

5.     What do you mean by switch reluctance motor? -April 2014

6.     Write any control method for switched reluctance motor. -April 2014

7.     Mention any two disadvantages of position sensor in switched reluctance motor. -April 2014

8.     Write any two application of switched reluctance motor. -April 2014

9.     State any two advantages of switched reluctance motor.

10.                        Give the relationship between fundamental switching frequency and speed of SRM.

PART-B

1.     Explain How Static Torque Produced In SRM (12) -Oct 2013

2.     Explain In Details Sensorless Operation Of SRM (12) -Oct 2013- April 2014

3.     Draw and explain the torque speed characteristics of switched reluctance motor. (12) -April 2014

4.     With neat sketch explain the construction and principle of operation of SRM. (12)

5.     Draw and explain SRM drive circuits for 3 phase SRM. (12)

UNIT-III

PART-A

1.     What Is Hybrid Stepper Motor?-Oct 2013

2.     Define Holding Torque-Oct 2013

3.     Draw The Dynamic Characteristics Of Stepper Motor-Oct 2013

4.     Mention The Different Types Of Stepper Motor-Oct 2013

5.     Mention the name of the two type of variable reluctance stepper motor. -April 2014

6.      Define step angle of stepper motor. -April 2014

7.     What are the two characteristics of stepper motor? -April 2014

8.      Define holding torque of stepper motor. -April 2014

9.     Mention few application of stepper motor.

10.                        State the principle of stepper motor.

11.                        List any two applications of stepper motor.

PART-B

1.     Explain The Construction And Operation Of Stepper Motor (12) -Oct 2013

2.     Draw The Block Diagram Of Closed Loop Control Of Stepper Motor And Explain (12) -Oct 2013

3.     Explain the working of a hybrid stepper motors. (12) -April 2014

4.     Draw the dynamic characteristics of stepper motor and explain. (12) -April 2014

5.     Explain at least any five applications of stepper motor. (12)

UNIT-IV

PART-A

1.     Give The EMF Equation Of Permanent Magnet BLDC Motor-Oct 2013

2.     Draw The BH Curve Of Permanent Magnet-Oct 2013

3.     Mention Any Two Applications Of Permanent Magnet BLDC Motor-Oct 2013

4.     What Are The Salient Features Of BLDC Motor? -Oct 2013

5.     What are the types of permanent magnet brushless motor? -April 2014

6.     Write down the EMF equation of brushless permanent magnet. -April 2014

7.     Draw the torque speed characteristics and indicate rated torque and peak torque of permanent magnet brushless DC motor. -April 2014

8.     Compare permanent magnet brushless DC motor with conventional DC motor. -April 2014

9.     Draw the demagnetization characteristic curve of permanent magnet.

10.                        What are the disadvantages of brushless DC motor as compared to - PMDC commutator motor?

11.                        Name the materials used for permanent magnet.

12.                        Write down the torque equation of Brushless D.C motor.

PART-B

1.     With neat sketches and waveforms explain the operation of Brushless DC motor with 180° and 120° magnet arcs. (12) -Oct 2013

2.     Draw the schematic of controller for brushless D.C motor and explain its (12) -Oct 2013

3.     Derive the EMF equation of permanent magnet brushless motor. (12) -April 2014

4.     With necessary sketch explain the operation of operation of brushless DC motor with 120  magnet arc. (12) -April 2014

5.     Draw the magnetic equivalent circuit of PMBLDC motor and Discuss on various parameters there in (12)

6.      (1) Bring about EMF and Torque equation of permanent magnet brushless D.C motor. (6) (2) Draw and explain Torque speed characteristics of brushless DC motor.(6)

UNIT-V

PART-A

1.     Which Type Of Supply Used In Hysteresis Motor?-Oct 2013

2.     Mention The Applications Of AC Series Motor. -Oct 2013

3.     State The Principle Of Linear Motor-Oct 2013

4.     State The Principle Of PMDC Motor-Oct 2013

5.     At synchronous speed what type of torque is present in hysteresis motor? -April 2014

6.     Write two applications Ac series motor. -April 2014

7.     Give the expression for synchronous speed of linear induction motor. -April 2014

8.     State two advantage of permanent magnet AC motor. -April 2014

9.     Where is linear motor used?

10.            What is the type of supply used in permanent magnet A.C. motor?

11.            What is linear motor?

12.            Give an application of permanent magnet D.C motor.

13.                                                                                                                     State the principle of hysteresis motor?

PART-B

1.     Briefly explain the principle of operation and characteristics of Hysteresis motor. Mention its applications..(12) - Oct 2013 -April 2014

2.     Construction And Operation Of AC Series Motor (12) -Oct 2013

3.     Draw and explain the torque current and torque  speed characteristics of permanent magnet DC motor. Also write the advantage of permanent magnet DC motor. (12) -April 2014

4.     Write short notes on 1. Permanent magnet AC motor. 2. Linear motor. (12)

5.     Write short notes on (12) 1. Linear motor. 2. A.C series motor          (12)

****** ALL THE BEST ******

23051-POWER SYSTEM-1 IMPORTANT QUESTIONS

23051-POWER SYSTEM-1 IMPORTANT QUESTIONS

DIPLOMA IN ELECTRICAL AND ELECTRONICS ENGINEERING

SUBJECT CODE      : 23051

SEMESTER               : V SEMESTER

SUBJECT TITLE      : POWER SYSTEM-1

STAFF-IN-CHARGE: N.SURESH KUMAR

IMPORTANT QUESTIONS

UNIT-I

PART-A

1.      State any two advantage of thermal power plant.-OCT 2013

2.      List out the different renewable energy sources. .-OCT 2013

3.      What is grid system? .-OCT 2013

4.      Define diversity factor. .-OCT 2013

5.      What Is The Electrical Machine Used In Winding Mill? - APRIL 2014

6.      Which Type Of Boilers Is Used In Thermal Power Plant? - APRIL 2014

7.      Define Plant Capacity Factor. - APRIL 2014

8.      Mention The Applications Of Fuel Cells. - APRIL 2014

9.      What are the conventional sources to general Electrical power?

10.  What is the purpose of surge tank?

11.  Give any two disadvantages of hydroelectric power plant.

12.  What is meant by stand-alone system?

13.  Give the renewable energy sources for generating Electrical power.

14.  What is meant by grid?

15.  What is meant by Tariff?

16.   State Kelvin’s law

PART-B

1.      What Are The Point To Be Consider For The Selection Of Site For A Thermal Power State Its Merits And Demerits.(12)-OCT 2013

2.      Draw The Schematic Diagram Of A Nuclear Power Plant And Explain Its Working. (12)-OCT 2013                                                                                                                    

3.      Explain The Renewable Energy Source Which Are Suitable For Direct Electrical Conversion (12) -APRIL 2014

4.      Write Notes On A)Pumped Storage Scheme B) Load Despatch Centre (12)-APRIL 2014

5.      List and explain the advantages of interconnected system.(12)

6.      Draw and explain the schematic arrangement of thermal power plant. (12)

7.      Draw and explain the schematic diagram of nuclear power plant. (12)

8.      A generating station has a maximum demand of 50 mw. Given the following data, calculate the cost per unit delivered. Capital cost – Rs. 95x105. Annual cost of fuel and oil Rs. 9x105 Taxes, wages and salaries – Rs. 6 x 105 Rate of Interest and depreciation – 10% Annual Load factor -50%. (12)

UNIT-II

PART-A

1.      State Kelvin’s Law. .-OCT 2013

2.      What Is Ferranti Effect? .-OCT 2013

3.      What Are The Merits Of ACSR Conductor Material Used For Transmission? .-OCT 2013

4.      Why The Transmission Line Conductors Are Interchanged At Regular Interval Along The Line? .-OCT 2013

5.      Mention The Type Of Supports Used In Oh Line. - APRIL 2014

6.      Classify Oh Transmission Line- APRIL 2014

7.      Mention Any Two Advantages Of Dc Transmission Over Ac Transmission- APRIL 2014

8.      What Do You Understand By The Term Dc Link? - APRIL 2014

9.      List the elements of a transmission line.

10.  Give any two limitations of Kelvin’s law.

11.  Give the types of line supports.

12.  Write the span lengths allowable for R.C.C. Poles.

13.  Give the properties of conductor materials used for O.H. transmission

14.  What is ferranti effect?

15.  Give any two advantages of suspension Insulators.

16.  What is string efficiency?

PART-B

1.      Draw The Layout Of Ac Power Supply Scheme And Explain The Various Stage. (12)-OCT 2013

2.      Explain The Following Line Supports With Merits And Demerits (I) Steel Tubular Poles (Ii) Rcc Poles And (Iii) Steel Tower. (12)-OCT 2013

3.      Dicuss In Detail About A) Ferranti Effect B)Corona (12)-APRIL 2014

4.      An Over Head 3 Phase Transmission Line Delivers 5000 Kw At 22kv At 0.8 Pf Lagging. The Resistance And Reactance Of Each Conductor Is 4 Ohm And 6 Ohm Respectively. Determine 1) Percentage Regulation % 2) Transmission Efficiency (12)-APRIL 2014

5.      Derive an expression for the sag in a transmission line conductor suspended between two supports at the same level. (12)

6.      Explain how to find the regulation and efficiency of short transmission lines. (12)

7.      State and explain Kelvin’s law. (12)

8.      Compare constant current and constant voltage HVDC systems. (12)

UNIT-III

PART-A

1.      What Are The Materials Used For Manufacturing Insulator? .-OCT 2013

2.      Define String Efficiency. .-OCT 2013

3.      How Cables Are Classified According To Voltage Range? .-OCT 2013

4.      What Is Mean By Grading Of Cables? .-OCT 2013

5.      Mention The Materials Suitable For Line Insulator. - APRIL 2014

6.      What Are All The Tests To The Conductor On Line Insulators- APRIL 2014

7.      Mention The Requirements Of UG Cable- APRIL 2014

8.      Mention The Type Of Grading Of Cables- APRIL 2014

9.      What is skin effect?

10.  Name the types of Insulators.

11.  Give any four reasons for failure of Insulators.

12.  Give any three properties of Insulating materials used in cables.

13.  Name the types of pressure cable.

14.  Name the types of grading of cables.

15.  What is symmetrical faults in power system?

16.  What is meant by Recovery voltage?

PART-B

1.      An Insulator String Consist Of 3 Units Each Having Safe Working Voltage Of 15kv. The Ratio Of Self Capacitance Of Each Unit Is 8:1. Find The Maximum Safe Working Voltage Of The String Efficiency. (12)-OCT 2013

2.      Explain With The Neat Sketch The Construction Of A Three Conductor UG Cable With Description On Various Parts. (12)-OCT 2013

3.      Discuss In Detail About The Properties And Causes Of Failures Of Insulators(12)-APRIL 2014

4.      With Test Circuit Diagram Explain Murray Loop Test (12)-APRIL 2014

5.      Bring out the reasons for the failure of Insulator. (6)

6.      Explain any two methods to improve the string efficiency. (6)

7.      Explain the construction of belted cable. (6)

8.      Explain capacitance grading of U.G. Cables. (6)

9.      Explain the various methods of testing of insulators. (12)

10.  Explain different types of laying of cables. (12)

UNIT-IV

PART-A

1.      What Is Function Of Switchgear? .-OCT 2013

2.      How The Circuit Breakers Are Classified? .-OCT 2013

3.      What Are The Requirements Of Fuse? .-OCT 2013

4.      Mention Any Two Causes For Over Voltage. .-OCT 2013

5.      Define The Term Current Chopping- APRIL 2014

6.      Mention The Types Of Ac Circuit Breakers - APRIL 2014

7.      What Is The Problem In Braking Dc Voltage- APRIL 2014

8.      Mention The Types Of Lightning Arresters- APRIL 2014

9.      Name the methods of laying underground cable

10.  What is switch gear?

11.  What are the factors responsible for the maintenance of arc between the contacts?

12.  Give any three advantages of SF6 circuit breaker.

13.  What is short time rating?

14.  Write the desirable characteristics of fuse.

15.  List the fundamental requirements of relay

16.  What is meant by backup protection?

PART-B

1.      Explain The Construction And Working Of Cross Blast Air Circuit Breaker. State  Its Merits And Demerits. (12)-OCT 2013

2.      Explain With A Neat Sketch The Working Of HRC Fuse With An Tripping Device. (12)-OCT2013

3.      With Neet Diagram Explain The Functionality Of Vacuum CB (12)-APRIL 2014

4.      Write Note On 1) Hrc Cartridge Fuse 2) Protection Against Lightning(12)-APRIL 2014

5.      Explain the construction and working principle of sulphur hexa fluoride. (6)

6.      circuit breaker and state its advantages. (6)

7.      Explain the construction and working of HRC fuse with tripping device. (12)

8.      Explain the construction and working principle of vacuum Circuit breaker. (12)

9.      Explain the construction and working of expulsion type lightning arrester. (12)

UNIT-V

PART-A

1.      What Are Basic Requirement Of A Fuse? .-OCT 2013

2.      Mention The Two Types Of Differential Relay. .-OCT 2013

3.      Where Distance Relay Are Used? .-OCT 2013

4.      What Is The Function Of Earthing Transformer? .-OCT 2013

5.      Classify The Relays Based On Operating Time- APRIL 2014

6.      Mention The Advantages Of Static Relay - APRIL 2014

7.      What Is The Uses Of Mho Relay - APRIL 2014

8.      Mention The Types Of Neutral Grounding-APRIL 2014

9.      What is the function of a fuse?

10.  What is static relay?

11.  What is meant by Primary protection?

12.  What is meant by grounding?

13.  List the types of Neutral grounding

14.  Give the types of static relays.

15.  List the effects of ungrounded Neutral.

16.  What is static relay?

PART-B

1.      Explain With A Neat Sketch The Construction, Working And Application Of Directional Over Current Relay. (12)-OCT 2013- APRIL 2014

2.      Explain The Following Of Grounding: (I) Resonant Grounding  (Ii) System Grounding. (12)-OCT 2013

3.      Explain The Operation Of Differential Relay With Simple Sketch (12)-APRIL 2014

4.      Explain the construction and working principle of earth leakage relay. (12)

5.      With necessary diagram explain resistance grounding. (12)

6.      Explain the construction and working principle of Earthing transformer. (12)