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UNIT I

PART A

Define electric motor.

Define electric generator.

Define excitation.

What are the methods of excitation?

What do you mean by self excited machine?

What do you mean by separately excitedmachine?

State the function of commutator.

What do you mean by commutation?

What is the purpose of brushes?

By which material yoke can be manufactured?

Why the brushes are made upon carbon?

What are the types of self excited generator?

Define shunt generator.

Define series generator.

Define compound generator.Draw the open circuit characteristics of dc

separately excited generator.

What do you mean by magnetization curve?

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Draw the load characteristics of separatelyexcited dc generator.

Draw the characteristics for DC shunt

generator.

Draw the characteristics of DC seriesgenerator.

Draw the characteristics of DC compoundgenerator.

What is the principle of operation of dc

generator?Write down faradey's law of electromagnetic

induction.

What is the principle of operation of DC motor?

State lenz's law.

How Lenz's law is helpful for the operation of

DC motor?

Write the significance of back e.m.f.

Define back e.m.f.

Write the e.m.f. equation of DC generator.

Write down the voltage equation of DC motor.

Write the torque equation of DC motor.

Draw the characteristics of DC shunt motor.

Draw the characteristics of DC series motor.

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Draw the characteristics of DC compoundmotor.

Differentiate differentially compound and

cumulatively compound motor.

What are the applications of DC shunt motor?

What are the applications of DC series motor?

What are the applications of DC compoundmotor?

Why shunt motor is called as constant speed

machine?

Why starter is needed in DC motor?

What is the advantage of 4 point starter over 3point starter?

State the function of no volt coil.

State the function of over load release.What is the advantage of conducting Swin-

burne's test?

Draw the diagram of ward-leanord system ofspeed control.

By which method, we can control the speed ofthe motor below the base speed?

By which method, the speed control of the DCmotor be above the base speed?

What are the various methods of speed controlof DC motor?

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Differentiate armature voltage control methodand field flux control method.

What do you mean by brake test?

PART B

Explain in detail the constructional details ofDC machine.

Derive the e.m.f. equation (8)

Draw and explain the characteristics of DCgenerator.

Derive the torque equation/

Write down the significance of back e.m.f.

Write down the principle of operation of DCmotor.

Draw and explain the characteristics of DC

motor.Draw and explain 3 point starter.

What is the draw back in 3 point starter andhow it is overcome in 4 point starter?

Explains the procedure of swin burne's test.

Draw and explain the speed control methods of

DC shunt motor.

Explain in detail about the ward-leonardsystem of speed control of DC motor.

Problem.

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UNIT II

PART A

State the principle of operation of transformer.

What are the types of transformer according toits construction?

Differentiate core type transformer and shelltype transformer.

Write down the e.m.f equation of transformer.Write down the transformation ratio.

Define magneting current component.

Define working current component.

Draw the vector diagram of transformer an noload.

How the resistance of the secondary bereferred in the primary?

Draw the approximate equivalent circuit of thetransformer.

Draw the vector diagram for the transformerunder resistive load.

Draw the vector diagram for the transformerunder inductive load.

Draw the vector diagram of the transformerunder comparative load.

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When the transformer is said to be ideal?

Define voltage regulation of transformer.

Define voltage regulation up.

Define voltage regulation down.

By conducting no load test, which losses canbe found out?

Which losses can be found out by conductingshort circuit test?

What are the tests to be conducted on thetransformer?

PART - B

Derive the e.m.f. equation of transformer.

Explain in detail about the transformer on noload.

Draw and explain ideal transformer. Draw itsvector diagram.

Obtain the equivalent circuit of thetransformer by conducting suitable tests.

Draw and explain in detail about thetransformer an load.

Derive the regulation formula for thetransformer.

Explain in detail about the testing proceduresfor the transformer.

Problem.

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UNIT III

PART A

Write the working principle of induction motor.

How RMF is produced with the help of 3 phasesupply?

Define slip.

Write the working principle of 3f induction

motor.Why 3f induction motor is called as rotating

transformer?

Can the rotor speed of induction motor besynchronous speed?

What are the types of induction motor?

Write down the torque equation of 3f inductionmotor.

Draw the slip-torque characteristics.

Draw the speed-torque characteristics.

State the relation between P2, Pc and Pm.

Draw the Power flow diagram of 3 phaseinduction motor.

Draw the equivalent circuit of 3 f inductionmotor.

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Why starter is necessary in AC inductionmotor?

What are the types of starters available to

start 3 f induction motor?

Why single phase induction motor is not selfstarting?

How single phase induction motor is made tostart?

How the rotor is classified in 3f induction

motor?How Rmf is produced in the stator of the

induction motor

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 fACsupply?

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

4. Explain the procedure to obtain the

equivalent circuit of 3 phase inductionmotor.

5. Derive the torque equation of 3 phaseinduction motor.

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

7. Explain in detail about (i) Star-delta starter

(ii) Auto transformer starter (iii) DOL starter.

8. Write short notes on single phasetransformer.

9. Why single phase induction motor is not selfstarting? Explain the methods available tostart the motor.

10. Write short notes on speed control of 3f

induction motor.

UNIT IV

PART A

What are the types of synchronous machines?

What is the basic principle of operation 3falternator?

Why stationary armature is there in 3f alternator?

Write down the e.m.f. equation of alternator.

What are the types of 3 f alternator?

Define voltage regulation of alternator?

What are the methods to find out voltage regulation?

Why synchronous impedance methods is called as pessimisticmethod?

What are the methods to find out voltageregulation

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Explain in detail the construction ofsynchronous machine.

Write short notes on (i) Brushless alternator

(ii) Reluctance motor (iii) Hysteresis motor(iv) Stepper motor.

UNIT V

PART A

What are the various sources of electric powergenerating system?

What is the purpose of step up transformer inelectrical power system?

What do you mean by carona loss?

What is meant by Ferranti effect?

What are the advantages of AC transmission?

What are the advantages of DC transmission?What are the types of distribution system?

What is EHUAC?

Define EHUDC.

What is the purpose of circuit breakers.

Define insulators.Why the transmission is done through under

ground cable?

What are the advantages of under groundcables?

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What are the types of under ground cables?

What are types of insulators?

What is pin insulator? Where it is used?

What is stay insulator? Where it is used?

What are the purposes of insulator?

Define service mains.

Define grid.

Differentiate feeders and distributors.

PART - B

Explain in detail, the single line diagram ofelectrical power system.

Explain in detail the various types oftransmission and distribution systems.

Distinguish EHUAC and EHUDC systems.

Explain in detail the substation lay out.

Write short notes as (i) Insulators (ii) cables.