B.E. 8 th SEMESTER POWER SYSTEM OPERATION ......Faculty of Degree Engineering - 083 Department of...

Faculty of Degree Engineering - 083 Department of Electrical Engineering -09

B.E. 8 th SEMESTER

POWER SYSTEM OPERATION AND CONTROL - MCQ

SUBJECT CODE: 2180909

Questions 1 to 4 refer to the figures given below:

Theinput-outputcurvesfortwounitswithsupplyinparallelacommonloadareshowninthe figure

Q1. Whenaloadof10MWisequallysharedbythetwogenerators,thecombined input mustbe

(A) 250x105kcal/hr

(B) 350x105kcal/hr

(C) 500x105kcal/hr

(D) 600x105kcal/hr


Q2. Ifthetwogeneratorshaveindividualratingsof10MWeach,asystemloadof16 MW should be sharedas

(A) 8 MW on eachgenerator (B) 10MWonAand6MWonB

(C) 10MWonBand6MWonA (D) 9MWonAand7MWonB

Q3.Loadsheddingisdone

(A) To reduce heatdemand

(B) To improve powerfactor

(C) Toruntheequipmentefficiency

(D) To repair themachine

Q4. Ifbothgeneratorshave2MWloadeachthenwhichofthefollowingstatementsis correct?

(A) GeneratorArunsathigherspeedascomparedtogeneratorB (B) GeneratorBrunsmoreefficientlyascomparedtogeneratorA

(C) InputtogeneratorAislessthan75%oftheinputtogeneratorB

(D) InputtogeneratorBislessthantheinputtogeneratorAbyabout23%

Questions 5 and 6 refer to the data given below:

AbulksupplywastakenbyalargeindustrialconsumerattherateofRs80perKWplus2 5 paisa perKWh

Q5. TheaveragechargeperKWhwhentheloadfactoris20% willbe

(A) 3cents

(B) 5cents

(C) 7cents

(D) cannotbedeterminedonthebasisoftheinformationprovided

Q6. TheaveragechargesperKWhwillbeleastwhentheplantloadfactoris (A)100%

(B)75%

(C)50%

(D)20%


Q7. Whichstatementaboutthedailyloadcurveisvalid?

(A) Theareaunderthecurvegivestheaveragedemand

(B) Theratiooftheareaunderthecurvestothetotalareaofrectangleinwhichitis

containedgivestheloadfactorfortheday

(C) Thepeakofthecurvegivesthe'installedcapacityoftheplant

(D) Theareaofthecurvesdividedbythenumberofhoursgivesloadfactor

Q8. AnEquipmentpurchasedforRs10,000twoyearsagohasamarketvalueofRs

12500atpresent.Itcanbeconcludedthat

(A) thevaluehasdepreciatedaccordingtostraightlinemethod

(B) thevaluehasdepreciatedaccordingtodiminishingvaluemethod

(C) thevaluehasdepreciatedaccordingtosinkingfundmethod

(D) thevaluehasappreciatedwiththetime

Q9. Inasteampowerplantwhichcomponentneedsmaximummaintenanceattention?

(A) Condenser

(B) Boiler

(C) Turbine

(D) Water treatment plant


FourloadsasshowninfiguregivenbelowareconnectedtoapowerstationAbsciseistimefrom

0to24hrsinallcases,OrdinaterepresentstheloadinKW

Q10. Whichloadhasthelowestaveragedemand?

LoadA

LoadB

LoadC

LoadD

Q11. Whichloadsoffertheidenticalaverageload?

(A) AandB

(B) BandC

(C) CandD

(D) A, B andD

Q12. Thepeakloadontheplantis


(A) 3000KW

(B) 3500KW

(C) 4000KW

(D) 4250KW

Q13. Theloadfactoroftheplantsupplyingpowertotheseloadswillbenearly

(A)11%

(B)15%

(C)18%

(D)21%

Q14. Thediversityfactoroftheplantsupplyingtheseloadswillbe

(A)0.5

(B)1.0

(C)1.5

(D) 0.2 Define

Q 15.

n

∑PGi−PD −PLoss=0 i=1

(A) Real Power balanceconstraints

(B) Generation capacity constraint

(C) Both A andB

(D) None ofthem


Gi Gi Gi

Q16. Pmin≤P≤Pmax,i=1,2,…….,



(C) Both A andB

(D) None ofthem

Q17. Sli≤ Smaxli, i = 1, ...,NL


(B) Generation capacityconstraint

(C) Securityconstraints

(D) None ofthem

Q18. F(P N

)=∑a+bP +c P2 Wherei=1, .......................... ,N Gi i i Gi

i=0 i Gi



(C) Security constraints

(D) None ofthem

Q19. Followingpowerplanthasinstantstarting

(A) nuclear powerplant

(B) hydro powerplant

(C) diesel powerplant

(D) both (b) and(c)


Q20. Whichofthefollowinggeneratingstationhasminimumruiningcost?

(A) Nuclear

(B) Hydro

(C) Thermal

(D) Diesel

Q21. This curve isshowing?

(A) Increment Fuel CostCurve

(B) Input OutputCurve

(C) Operating costcurve

(D) None ofthese

Q22. Optimal system operationinvolved

(A) Economy ofoperation

(B) Systemsecurity

(C) Emissionsatcertainfossil-fuelplants

(D) All ofabove

Q23. Optimalsystemoperationmaysayas

(A) Economy of operation of PowerSystem

(B) Emission of operation of PowerSystem


(C) BothAandB

(D) None ofthem

Q24. Theeconomicdispatchproblemisusetocalculate

(A) Minimizethetotalcostofgeneratingrealpower

(B) Minimizethetotalcostofgeneratingreactivepower

(C) BothAandB

(D) None ofthem

Q25. Optimal system operationinvolved

(A) Economy ofoperation

(B) Systemsecurity

(C) BothAandB

(D) None ofthem

Q26. Which power plant is neglecting operatingcost

(A) Hydroplant

(B) Thermalplants

(C) Nuclearplant

(D) None ofthem

Q27. Which power plant is considering operatingcost

(A) Hydroplant

(B) Thermalplants

(C) Nuclearplant

(D) BothBandC


Q28. Input-outputcurveofageneratingunitdrawinbetween

(A) Operating cost and powergeneration

(B) PowerGenerationAndOperatingCost

(C) Both OfAbove

(D) None OfThese

Q29. Operating cost consistof

(A) Fuelcost

(B) Maintenancecost

(C) BothAandB

(D) OnlyA

Q30. Incremental cost curveis

(A) Slope of Input outputcurve

(B) Slope of loadcurve

(C) BothAandB

(D) None ofabove

Q31. Ageneratingstationisnoteconomicalat

(A) AbovethePGimin

(B) Equal to thePGi

(C) BelowthePGimax

(D) BelowthePGimi

Q32. Ageneratingstationisnoteconomicalat

(A) EqualtothePGimin

(B) Equal to thePGi

(C) AbovethePGimax

(D) AbovethePGimin

Q33. Ageneratingstationiseconomicalat

(A) EqualtothePGimin

(B) Equal to thePGi

(C) BelowthePGimax


(D) All theabove

Q34. Incrementalfuelcost(IC)defineas

(A) IC= dCi

d PGi

(B) IC=dPGi

d Ci N

(C) IC=∑ a + b P+c P2

i i Gi iGi

i=0

(D) None ofthese

Q35. The system constraintare

(A) EqualityConstraint

(B) Inequalityconstraint

(C) BothAandB

(D) None ofthese

Q36. IncrementtheICvaluebyΔICincaseof

n

(A) ∑PGi−PD<0 i=1

n

(B) ∑PGi−PD >0 i=1

n

(C) ∑PGi−PD=0 i=1

(D) None ofthese

Q37. IncrementtheICvaluebyΔICincaseof

n

(A) ∑PGi−PD <0 i=1

n

(B) ∑PGi−PD>0 i=1

n

(C) ∑PGi−PD=0 i=1

(D) None ofthese


Y

Y

Y

Y

= ∧ =

Q38.“Itsloadingfromnowonisheldfixedatthisvalueandthebalanceloadisthen

sharedbetweentheremaininggeneratorsonequalincrementalcostbasis.”Thistheory knows

(A) Patton’s securitytheory

(B) Kuhn-Tuckertheory

(C) BothAandB

(D) None ofthese

Q39. IncrementalfuelcostsinrupeesperMWhforaplantconsistingoftwounitsare:

IC1=0.20PG1+40

IC2=0.25PG2+30

Where PG1 and PG2(inMW)arepowergeneratedbyboththeunitsforatotaldemandof

250MW,Thetotalsharedbythetwounitsare

(A) P

350 P

G1 3 400

G2 3

(B) PG 1=100∧ PG2=250

(C) PG 1=125∧ PG2=125

(D) PG 1=150∧ PG2=100

Q40.“Itsloadingfromnowonisheldfixedatthisvalueandthebalanceloadisthen

sharedbetweentheremaininggeneratorsonequalincrementalcostbasis.”Thistheory knows

(A) Patton’s securitytheory

(B) Kuhn-Tuckertheory

(C) BothAandB

(D) None ofthese

Q41. Dynamicprogrammingmethodequationis

(A) FN

(B) FN

(x)=min{F

(x)=min{F

(y)+F

(y)+F

N−1

N−1

( x− y ) }

( x+ y )}

(C) FN (x)=min{F

N−1 (y)+FN ( x− y ) }

(D) FN (x) )=min{F (y)+F N+1 ( x− y )}

Questions 42 to 44 refer to the data given below:

N

N

N


Theinput-outputcurveofa0.5MWgeneratingstationsisdefinedby I=30+0.8L+0.5L2

Where I is in MKcal and L is in megawatts

Q42. Theinputwhentheplantwasrunningonnoloadwas

(A) 0.5kcal

(B) 31.3kcal

(C) 30 x 106kcal

(D) zero

Q43. Totalinputwhentheplantwasgenerating35MWwas

(A) 181x106kcal/hr

(B) 250x106kcal/hr

(C) 362.5 x 106kcal/hr

(D) 582xl26kcal/hr

Q44. Whentheloadonthegeneratorwas25MWtheheatrateinkcal/MWhrwas nearly

(A)16x106

(B)20x106

(C)30x106

(D) 31.3 x 106


ManufacturerAoffershisequipmentcostingRs150,000+45xKW the equipmentis

guaranteedtogivethefollowingoperatingcostRs18+0.007KWh

ManufacturerBoffershisequipmentcostingRs1,12000+50xKWTheoperatingcostis guaranteed as Rs 16.50 +

0.0072KWh


KW indicates machine rating and KWh indicates output

Q45. Whichmachineischeapertoownin5000KWrange

(A) MachinesuppliedbymanufacturerA

(B) MachinesuppliedbymanufacturerB

(C) Both have identical initialcost

(D) Both have identical operatingcost

Q46. AtwhatKWratingtheinitialcostofthetwomachineswillbeidentical?

(A) 5500KW

(B) 6000KW

(C) 7600KW

(D) 8500KW

Q47. AtwhatratinginKWhthetwosetswillbeequallyeconomicaltooperate?

(A) 5000KWh

(B) 7500KWh

(C) 75000KWh

(D)50,000 KWh

Q48. Power factor is givenby

(A) KWh /KW

(B) activepower/reactivepower

(C) reactivepower/activepower

(D) KW /KWh

Q49. Forthesamecylinderdimensionsandspeed,whichenginewillproduceleast power?

(A) Petrolengine


(B) Dieselengine

(C) Super chargedengine

(D) All will produce samepower

Q50. ForunderwatermovementSubmarinesarepoweredby?

(A) Dieselengines

(B) Airmotors

(C) Batteries

(D) Steamaccumulators

Q51. Ships are generally poweredby

(A) Dieselengines

(B) Hydraulicturbines

(C) Nuclear powerplants

(D) Steamaccumulators

Q52. Aturbojetaeroplanehas

(A) Noblades

(B) Twoblades

(C) Threeblades

(D) Fourblades

Q53. Aninterconnectedsystemhasthefollowingplants I

runofftheriverplant

II Nuclearpowerplant

III Steampowerplant

IV Hydro-electric plant withstorage


V Diesel engineplant

Which two plants can be exclusively used for base load?

(A) I andII

(E) II andIII

(F) IIandIV

(G) II andV

Q54. Whichplantcanbeusedexclusivelyforpeakload?

(A) I

(B) III

(C) IV

(D) V

Q55. Directconversionofbeatintoelectricalenergyispossiblethrough

(A) Magneto hydrodynamicgenerators

(B) Solarcells

(C) Fuelcells

(D) notpossible

Q56. Inafuelcellelectricityisproducedby

(A) Combustionoffuelinabsenceofoxygen

(B) Oxidation offuel

(C) Thermionicaction

(D) Any of theabove

Q57.AcertainplanthasfixedcostofRs40,000andasalvagevalueofRs4000atthe

endofausefullifeof20yearsThedepreciatedvalueoftheplantattheendof10years

willbeleast(interestratebeing6%compoundedannually)whencalculatedby

(A) Straight linemethod

(B) Sinking fundmethod


(C) Diminishing valuemethod

Q58. Intheaboveproblemthevaluewillbehighestwhencalculatedby

(A) Straight linemethod

(B) Sinking fundmethod

(C) Diminishing valuemethod

Q59. Lowpowerfactorisusuallynotdueto

(A) Incandescentlamp

(B) Inductionmotors

(C) Arclamps

(D) Fluorescenttubes

Q60. WhichtypeofplanthastheleastrunningcostperKWhofenergygenerated?

(A) Hydro-electricplant

(B) Thermal powerplant

(C) Nuclear powerplant

(D) Diesel powerplant

Q61. Base load plantshave

(A) Highcapitalcost,highoperatingcostandhighloadfactor

(B) Highcapitalcost,lowoperatingcostandhighloadfactor

(C) Lowcapitalcost,lowoperatingcostandlowloadfactor

(D) Lowcapitalcost,highoperationcostandhighloadfactor


Q62. Whichalternatorwillhavemorenumberofpoles

(A) Coupled to hydraulicturbine

(B) Coupled to steamturbine

(C) Coupled to gasturbine

(D) Allwillhavesamenumberofpoles

Q63. Whichalternatorusuallyrunsatslowspeedascomparedtoothers

(A) Coupled to gasturbine

(B) Coupled to steamturbine

(C) Coupled to hydraulicturbine

(D) Coupled to dieselengine

Q64. Inathermalpowerstationofmoderatesize,theelectricalpowerisgeneratedata voltageof

(A) 115V

(B) 230V

(C) 440V

(D) 11kV

Q65. Theresistanceofthedryskinofhumanbody,betweenthetipofthelefthand

fingerandrighthandfinger,isoftheorderof

(A) 100ohms

(B) 1000ohms


(C) 10,000ohms

(D) 100,000 ohms

Q66. Iftheresistanceofdryskinofhumanbodyis100,000ohms,theresistanceofthe wet body willbe

(A) 100,000 ohms

(B) 200,000 ohms (C)

5000,000 ohms

(D) 5000ohms

Q67. Theeffectofelectricshockonhuman,bodydependson

(A) Voltage

(B) Current

(C) Duration ofcontact

(D) All of theabove

Q68. Acurrentof10millamperesthroughhumanbody

(A) Will cause mildsensation

(B) Will affect musclecontrol

(C) Will affectbreathing

(D) Will causedeath

Q69. Deathisalmostcertainwhenthecurrentthroughhumanbodyis

(A) 10 millamperes


(B) 20 millamperes

(C) 40 millamperes

(D) 100milliamperes

Q70. For extinguishing electricalfires

(A) Water should beused

(B) Carbondioxidefireextinguishershouldbeused

(C) Foamtypefireextinguishershouldbeused

(D) Carbontetrachloridefireextinguishershouldbeused

Q71. Firstaidforelectricshockvictimis

(A) Bandage

(B) Massage

(C) Pouring water onbody

(D) Artificialrespiration

Multiple Choice Questions of Economics of Power Generation (168-182):

Q72. Whenapowerplantisnotabletomeetthedemandofconsumersitwillresortto

(A) Penalizinghighloadconsumersbyincreasingthechargesforelectricity

(B) Power factor improvement at thegenerators

(C) Efficient plantoperation

(D) Loadshedding.

Q73. Load shedding is possiblethrough

(A) Voltagereduction

(B) Frequencyreduction

(C) Switching off theloads


(D) Any of theabove.

Q74. Whichofthefollowingpowerplantscangeneratepoweratunpredictableor uncontrollabletimes?

(A) Wind powerplant

(B) Tidal powerplant

(C) Solar powerplant

(D) Anyoftheabove.

Q75. Directconversionofheatintoelectricalpowerispossiblethrough

(A) Thermionicconverter

(B) Fuelcell

(C) Batteries

(D) all of theabove.

Q76. Inafuelcellpositiveelectrodeisof

(A) Oxygen

(B) Ammonia

(C) Hydrogen

(D) Carbonmonoxide.

Q77. AllofthefollowingaresourcesofborrowingmoneyEXCEPT

(A) Debentures

(B) Bonds

(C) Share

(D) Fixeddeposits.


Q78. Ideallydepreciatedvalueoftheplantplustheaccumulationinthedepreciation fund should be equalto

(A) Salvagevalue

(B) Obsolescencerate

(C) Sinkingfund

(D) Original investedcapital.

Q79. Inpowerplantsinsurancecoverisprovidedfor

(A) Equipmentonly

(B) Skilled workersonly

(C) Unskilled workersonly


Q80. Debenture :Interest::

(A) Capital:Depreciation

(B) Insurance:Mishap

(C) Sinking fund:Amortization

(D) Shares:Dividend.

Q81. Maximumdemandtariffisgenerallynotappliedtodomesticconsumersbecause

(A) They cannot affordtoday

(B) They consume lesspower

(C) Their load factor islow


(D) Their maximum demand islow.

Q82. Howmuchmustbedepositedattheendofeachyearinasinkingfundfor15

yearstoaccumulateRs1000ifinterestisat5percent?

(A) Rs46.34

(B) Rs54.55

(C) Rs 59.50

(D) Rs 60.00.

Q83. IfRs.50weredepositedattheendofeachyearfor12yearsinasinkingfund

earning6%,thetotalaccumulationwouldbe

(A) Rs 1000 (B)

Rs 925.50 (C) Rs

843.50 (D)

Rs799.75.

Q84. Anadvantageofstaticcapacitorforpowerfactorimprovementis

(A) Lowlosses

(B) Little maintenancecost

(C) Case ininstallation

(D) All of theabove.

Q85. AllofthefollowingarerepayableaftersometimeEXCEPT

(A) Bonds


(B) Shares

(C) Cashcertificates

(D) Fixeddeposits

Q86. The usual valueof

(A) Diversityfactorislessthanoneanddemandfactorismorethanone

(B) Diversityfactormorethanoneanddemandfactorislessthanisone

(C) Diversityfactoraswellasdemandfactorislessthandemand

(D) Diversityfactoraswellasdemandfactorismorethanone.

Multiple Choice Questions of Economics of Power Generation (183-197)

Q87. Theamountrepaidtoapersonattheendof15years,whoinvestsRs12,000at4

percentinterestcompoundedannually,willbe

(A) Rs12,400

(B)Rs16,120

(C)Rs21,612

(D) Rs 26,121.

Q88. WhatisthepresentworthofreceivingRs1000twentyyearsfromnowifmoney

canearn5%interestcompoundedannually?

(A) Rs376.93

(B)Rs445.50

(C)Rs500.00

(D) Rs 617.27.


Questions 185 to 187 refer to data given below:

Rs 10,000 are invested for 20 years at 6 percent.

Q89. Theamountaccumulated,whentheinterestiscompoundedannuallywillbe (A) Rs27,020

(B)Rs30,270

(C)Rs32,070

(D) Rs 35,600.

Q90. Theamountaccumulatedwhentheinterestiscompoundedsemi-annuallywillbe (A) Rs32,070

(B)Rs32,474

(C)Rs,32,620

(D)Rs32,888.

Q91. Theamountaccumulatedwhentheinterestiscompoundedmonthlywillbe (A) Rs32,070

(B)Rs32,620

(C)Rs32,898

(D) Rs 33,100.

Q92. Astheloadfactorapproachesunity,theshapeofloaddurationcurvewillbe nearly


(A) Lshaped

(B) Inverted Tshaped

(C) Triangular

(D) Rectangular.

Q93. Whenmaximumandaverageloadsareequal,theloadfactorwillbe

(A) Zero

(B) 0.01

(C)0.5

(D)1.0

Q94. Whichofthefollowingrelationisincorrect?

(A) Capacityfactor=UtilizationfactorxLoadfactor

(B) LoadfactorxMaximumload=Averageload

(C) DemandfactorxConnectedload=Maximumdemand

(D) None of theabove.

Q95. Capacityfactorandloadfactorbecomeidenticalwhen

(A) Peakloadisequaltothecapacityoftheplant

(B) Averageloadishalfthecapacityoftheplant

(C) Averageloadissameaspeakload

(D) Groupdiversityfactorisequaltopeakdiversityfactor.

Q96. Alowutilizationfactorforaplantindicatesthat


(A) Plant is undermaintenance

(B) Plantisusedforbaseloadonly

(C) Plantisusedforstandbypurposeonly

(D) Plantisusedforpeakloadaswellasbaseload.

Questions 95 to 96 refer to the following data:

Power plants considered are

I. Diesel

II. Thermal

III. Hydro

IV. Nuclear.

Q97. PlantsinascendingorderofcapitalcostperMWare

(A) I, II, III,IV

(B) II,III,IV,I

(C) III,IV,I,II

(D) IV.III,I,II

Q98. Plantsindescendingorderoftheirexpectedusefullifeare

(A) I,III,II,IV

(B) II,I,III,IV

(C) III,II,IV,I

(D) IV, I, II,III.


Q99. PlantsinascendingorderoftheiroperatingcostperMWHgeneratedare

(A) IV,I,II,III

(B) III,II,IV,I

(C) II,I,III,IV

(D) I,III,II,IV

Q100. Sinking fundis

(A) Initialvalue-Salvagevalue

(B) Capitalcost-Operatingcost

(C) Periodicalmaintenance-Breakdownmaintenance

(D) Capital cost / Usefullife.


1 D 21 A 41 A 61 B 81 D

2 B 22 D 42 C 62 A 82 A

3 A 23 A 43 C 63 C 83 C

4 C 24 A 44 A 64 D 84 D

5 C 25 C 45 B 65 D 85 B

6 A 26 A 46 C 66 D 86 B

7 D 27 D 47 C 67 D 87 C

8 D 28 A 48 B 68 A 88 A

9 B 29 C 49 A 69 D 89 C

10 C 30 A 50 C 70 D 90 C

11 D 31 D 51 A 71 D 91 D

12 D 32 C 52 A 72 D 92 D

13 A 33 D 53 A 73 D 93 D

14 B 34 A 54 D 74 D 94 D

15 A 35 C 55 A 75 A 95 A

16 B 36 A 56 B 76 A 96 C

17 C 37 B 57 C 77 C 97 A

18 C 38 B 58 B 78 D 98 C

19 D 39 A 59 A 79 D 99 B

20 B 40 B 60 A 80 D 100 A


Unit -2

Q101. Load curve helps indeciding

(A) Sizes of the generationunits

(B) Totalinstalledcapacityoftheplant

(C) Operating schedule of generatingunits


Multiple Choice Questions of Economics of Power Generation (91-106):

Q102. Majorshareofpowerproducedisthrough

(A) Thermal powerplants

(B) Hydro electric powerplants

(C) Nuclear powerplants

(D) Diesel powerplants

Q103. Essentialrequirementofpeakloadplant

(A) Itshouldbecapableofstandingquickly

(B) It should be run at highspeed

(C) Itshouldprovideathighvoltage

(D) Itshouldbesmallinsize

Q104. Whichofthefollowingplantsisalmostinevitablyusedasbaseloadplant?

(A) Gas turbineplant

(B) Diesel engineplant

(C) Pumped storageplant

(D) Nuclear powerplant

Q105. Athermalpowerstationwasdesignedtobumcoalcontaining12%ash

Whentheplantactuallystartedoperatingcoalhaving22%ashwasmadeavailable

Whichunitoftheplantwillneedmajormodifications?

(A) Water treatmentplant


(B) Pulverizingunit

(C) Ash handlingunit

(D) Coolingtowers

Q106. Efficiencyissecondaryconsiderationincaseof

(A) peak loadplants

(B) Base loadplants

(C) Bothpeakloadandbaseloadplants

(D) None of theabove

Q107. Whichofthefollowingplantswilltakeleasttimeinstartingfromcoldconditions to full

loadoperation?

(A) Nuclear powerplant

(B) Steam powerplants

(C) Hydro-electricplant

(D) Gas turbineplant

Q108. During loadshedding

(A) System voltage isreduced

(B) System frequency isreduced

(C) Some loads are switchedoff

(D) System power factor ischanged

Q109. Forthesameplantsize,initialcostofwhichplantisthehighest?

(A) Steampowerplant

(B) Diesel engineplant

(C) Nuclear powerplant


(D) Gas turbineplant

Q110.Aconsumertakesasteadyloadof200kWatapowerfactorof0.85laggingfor8

hoursperdayand315daysperannum.TheannualpaymentunderthetariffofRs80per

annumperkAplus10centsperkWhwillbe

(A) Rs 5040 (B)

Rs 50,400 (C) Rs

69,200 (D)

Rs88,400


Theestimatedtotalannualoperatingcostandcapitalchargesfortwoproposedpowerstations

aregivenbythefollowingexpressions

AnnualcostofstationA=Rs(600,000+3.0kW+0.015kWhr)AnnualcostofstationB=Rs

(750,000+5.0kW+0.014kWhr)

WherekWrepresentsthecapacityofthestationandkWhrepresentsthetotalannualoutput

Loaddurationcurveoftheplantisshowninthefiguregivenbelow

Q111. Whichstationmaybeselectedforbaseload?

(A) StationA

(B) StationB


(C) Any of theabove

Q112. Baseloadplantshouldbeoperatedannuallyfor

(A) 500hrs

(B) 1000hrs

(C) 2000hrs

(D) 5000hrs

Q113. Thecapacityofthebaseloadplantshouldnotbelessthan

(A) 3860kW

(B) 4180kW

(C) 5000kW

(D) 5500kW

Q114. TotalkWhsuppliedbytheplantis (A) 10.l

x106

(B)15x106

(C)18x106

(D) 21.9 x 106

Q115. TotalkWhtobesuppliedbybaseplantmustbe (A) 19 .76

x106

(B) 15.34 x 106

(C)14.1x106

(D)10.3x106


Q116. Foraloadflowsolutionthequantitiesnormallyspecifiedatavoltagecontrolled busare:

(A) P andQ

(B) PandIVI

(C) QandIVI

(D) P andᵟ

Q117. Fora15-buspowersystemwith3voltagecontrolledbus,thesizeofJacobian

matrixis(a)11x11(b)12x12(c)24x24(d)28x28.

In the solution of load-flow equation, Newton-Raphon (NR) method is superior to the Gauss-

Seidal (GS) method, because the

(A) timetakentoperformoneiterationintheNRmethodislesswhencomparedto

thetimetakenintheGSmethod

(B) numberofiterationrequiredintheNRmethodismorewhencomparedtothatin the GSmethod

(C) numberofiterationsrequiredisnotindependentofthesizeofthesysteminthe NRmethod

(D) convergencecharacteristicoftheNRmethodarenotaffectedbytheselectionof slackbus.

Q118. Whichoneofthefollowingmatricesrevealsthetopologyofthepowersystem network?

(A) Bus incidencematrix

(B) Primitive impedancematrix

(C) Primitive admittancematrix

(D) Bus impedancematrix.

Q119. Inload-flowanalysis,theloadatabusisrepresentedas


(A) aconstantcurrentdrawnfromthebus

(B) aconstantimpedanceconnectedatthebus

(C) constantrealandreactivepowersdrawnfromthebus

(D) avoltage-dependentimpedanceatthebus. (E)

Q120. InGauss-Seidelmethodofpowerflowproblem,thenumberofiterationsmaybe re-

ducedifthecorrectioninvoltageateachbusismultipliedby

(A) Gaussconstant

(B) Acceleration constant

(C) Deceleration constant

(D) Blockingfactor.

Q121. Considerthefollowingstatements:1.ItiseasiertoconstructtheYBusmatrixas

comparedtoZBus.2.ZBusisafullmatrixwhileYbusissparse.3.Y-buscanbeeasily

modifiedwheneverthenetworkchangesascomparedtotheZBus.Whichofthese statements are correct?

(A) 1and2

(B) 2and3

(C) 1and3

(D) 1, 2 and3.

Q122. Inloadflowstudiesofapowersystem,avoltagecontrolbusisspecifiedby Real power and

reactivepower

Real power and voltage magnitude Voltage

and voltage phase angle


Reactive power and voltagemagnitude.

Q123. Atslackbus,whichoneofthefollowingcombinationsofvariablesisspecified?

(A) I VI,ᵟ

(B) P,Q

(C) P, I VI

(D) Q,IVI.

Q124. Considerthefollowingquantities:1.Realpower3.Powerfactor5.Busvoltage magnitude

2. Reactive power 4. Input current 6. Bus voltage phase-angle.

Forthepurposeoftheloadflowstudiesofapowersystem,eachbusornodeisassociatedwith

whichoneofthecombinationsoftheabovefourquantities?

(A) 1, 3, 4 and 5

(B) 1, 2, 3 and 4

(C) 2,3,5and6

(D)1,2,5and6.

Q125. Normally ZBUSmatrix isa

(A) Nullmatrix

(B) Fullmatrix

(C) Sparsematrix

(D) Unitymatrix.

Q126. Gausss-Seideliterativemethodcanbeusedforsolvingasetof

(A) Linear differential equationsonly


(B) Linear algebraic equationsonly

(C) Bothlinearandnonlinearalgebraicequations

(D) Bothlinearandnonlineardifferentialequations

Q127. Apowersystemconsistsof300busesoutofwhich20busesaregeneratorbuses,

25busesaretheoneswithreactivepowersupportand15busesaretheoneswithfixed

shuntcapacitors.Alltheotherbusesareloadbuses.Itisproposedtoperformaloadflow

analysisforthesystemusingNewton-Raphsonmethod.ThesizeoftheNewton-

Raphson Jacobian matrix is (a)

553 x553

(b)540x540

(c)555x555

(d)554x554

Q128. Inload-flowanalysis,theloadatabusisrepresentedas

(a) Aconstantcurrentdrawnfromthebus

(b) Aconstantimpedanceconnectedatthebus

(c) Constantrealandreactivepowersdrawnfromthebus

(d) Avoltage-dependentimpedanceatthebus

Q129. Economicschedulingofgenerationisperformedforaperiodof

(a) 1/2hr

(b) 24hr

(c) 1sec

(d) 1week

Q130. Theinput-outputcharacteristicisplotted


(a) Fuel input Vs poweroutput

(b) Fuel input Vstime

(c) Fuel rate Vs poweroutput

(d) Fuel rate Vs energyoutput

Q131. Hearratecurveisplottedin

(a) k-cal/kwhr VsKW

(b) K-cal/hr VsKW

(c) k-cal/KW VsKw

(d) K-cal VsKW

Q132. Incrementalproductioncostandincrementalfuelcostare

(a) both thesame

(b) IPC>IFC

(c) IPC<IFC

(d) They are notrelated

Q133. Inpowersystemeachbusisassociatedwithhowmanyquantities.

(a) 4

(b) 3

(c) 5

(d) none

Q134. Ifrealandreactivepowercomponentsarespecifiedthenitiswhichtypeofbus.

(a) PQbus


(b) PVbus

(c) slackbus

(d) none

Q135. Forwhichbusinthepowersystemthevoltagemagnitudecorrespondingtothe

generationvoltageandrealpowercorrespondingtoitsratingsarespecified.

(a) PQbus

(b) PVbus

(c) slackbus

(d) none

Q136. Whichbusisinthepowersystemismadetotakeadditionalrealandreactive power to supply

transmissionlosses.

(a) PQbus

(b) PVbus

(c) slackbus

(d) none

Q137. Forwhichbuswehavetofindoutthevoltagemagnitudeandphaseangleofthe

busthroughtheloadflowsolution.

(a) PQbus

(b) PVbus

(c) slackbus

(d) none

Q138. Forwhichbuswehavetofindoutthereactivepowergenerationandphaseangle of the bus through the load

flowsolution

(a) PQbus

(b) PVbus


(c) slackbus

(d) none

Q139. DiagonalelementoftheYBUSmatrixisselfadmittance.

(a) True

(b) false

Q140. IBUS=YBUSVBUS,istheequationfornbussystem,inthisthematixsizeofYBUSisnXn.

(A) True

(B) False

(C) Nonepossible

Q141. IBUS=YBUSVBUS,istheequationfornbussystem,inthisthematixsizeofYBUSisnX1.

(a) True

(b) False

Q142. IBUS=YBUSVBUS,istheequationfornbussystem,inthisthematixsizeofYBUSis

(a) nXn

(b) 1Xn

(c) nX1

(d) 1X1

Q143. IBUS=YBUSVBUS,istheequationfornbussystem,inthisthematixsizeofIBUSis

(A) nXn


(B) 1Xn

(C) nX1

(D) 1X1

Q144. IBUS=YBUSVBUS,istheequationfornbussystem,inthisthematixsizeof VBUSis

(a) nXn

(b) 1Xn

(c) nX1

(d) 1X1

Q145. YBUSisthenXnmatrix,wherenisthenumberofbuses.

(a) true

(b) false

Q146. YBUSisthesymmetricmatrix

(a) true

(b) false

Q147. DiagonalelementoftheYBUSmatrixis

(a) selfadmittance

(b) transferadmittance

(c) both

(d) none

Q148. off-DiagonalelementoftheYBUSmatrixis

(a) selfadmittance

(b) transferadmittance

(c) both


(d) none

Q149. ZBUSisafullmatrix

(a) true

(b) false

Q150. Forconveniencewhichbusisconsideredasslackbus.

(a) Firstbus

(b) lastbus

(c) middlebus

(d) none.

Q151. SlackbusisalsocalledSwingbus

(a) true

(b) false

Q152. slackbusisalsocalledReferencebus

(a) true

(b) false

Q153. LoadbusisalsocalledPVbus

(a) true

(b) false

Q154. LoadbusisalsocalledPQbus

(a) true

(b) false

Q155. generator bus is also called PQbus

(a) true

(b) false


Q156. generator bus is also called PVbus

(a) true

(b) false

Q157. Loadflowsolutionisthesolutionunderwhichcondition

(a) steady statecondition

(b) transientcondition

(c) both

(d) none

Q158. Loadflowsolutionforpowernetworkcanbeworkedoutoperationunder

(a) balancedcondition

(b) unbalancedcondition

(c) both

(d) none

Q159. Inpowersystemeachbusisassociatedwith

(a) fourquantities

(b) threequantities

(c) fivequantities

(d) none

Q160. Ifrealandreactivepowercomponentsarespecifiedthenitiswhichtypeofbus.

(a) loadbus

(b) generatorbus

(c) slackbus

(d) none


Q161. Forwhichbusinthepowersystemthevoltagemagnitudecorrespondingtothe

generationvoltageandrealpowercorrespondingtoitsratingsarespecified

(a) loadbus

(b) generatorbus

(c) slackbus

(d) none

Q162. Whichbusisinthepowersystemismadetotakeadditionalrealandreactive power to supply

transmissionlosses.

(a) loadbus

(b) generatorbus

(c) slackbus

(d) none

Q163. Forwhichbuswehavetofindoutthevoltagemagnitudeandphaseangleofthe

busthroughtheloadflowsolution.

(a) loadbus

(b) generatorbus

(c) slackbus

(d) none

Q164. Forwhichbuswehavetofindoutthereactivepowergenerationandphaseangle of the bus through the load

flowsolution

(a) loadbus

(b) generatorbus

(c) slackbus

(d) none

Q165. slackbusisinthepowersystemismadetotakeadditionalrealandreactive power to supply

transmissionlosses.


(a) true

(b) false

Q166. Forgeneratorbuswehavetofindoutthevoltagemagnitudeandphaseangleof

thebusthroughtheloadflowsolution

(a) True

(b) False

Q167. Forgeneratorbuswehavetofindoutthereactivepowergenerationandphase angle of the bus through

the load flowsolution.

a) true

b) false

Q168. Thevoltagecontrolledbusistreatedasaloadbusinsubsequentiterationwhenits Voltage limit isviolated.

(a) True

(b) False

Q169. Thevoltagecontrolledbusistreatedasaloadbusinsubsequentiterationwhen

its:activepowerlimitisviolated.

(a) true

(b) false

Q170. TheloadflowsolutionisalwaysassuredincaseofNewton-Raphsonmethod.

(a) True

(b) False

Q171. Thebusadmittancematrix(Ybus)ofapowersystemisSymmetricmatrix.

(a) true

(b) false


Q172. Thebusadmittancematrix(Ybus)ofapowersystemisSparsematrix.

a) true

b) false

Q173. Thebusadmittancematrix(Ybus)ofapowersystemisequaltoZbusmatrix.

(a) True

(b) False

Q174. Thevoltagecontrolledbusistreatedasaloadbusinsubsequentiterationwhen its:

a) Voltage limit isvoilated

b) active power limit isvoilated

c) Reactive power limit isvoilated

d) Phase angle limit isvoilated

Q175. Theloadflowsolutionisalwaysassuredincaseof:

(a) Newton-Raphsonmethod

(b) Gaussmethod

(c) Gauss -Seidelmethod

(d) None of these methodguarantees

Q176.ComparedtoGauss-Seidelmethod,Newton-Raphsonmethodtakes: (a)less number

ofiterations

(b)morenumberofiterations

(c)equalnumberofiterations none

ofthese


Q177.ComparedtoGauss-Seidelmethod,Newton-Raphsonmethodtakes: (a)less time

periteration

(b) moretimeperiteration

(c)equaltimeperiteration

(d)none ofthese

Q178. Atslackbus,whichoneofthefollowingcombinationofvariablesisspecified?

(a) |V|,δ

(b) P,θ

(c) P,|V|

(d) θ,|V|

Q179. AtGeneratorbus,whichoneofthefollowingcombinationofvariablesis specified?

(a) |V|,δ

(b) P,|V|

(c) P,θ

(d) θ,|V|

Q180. AtLoadbus,whichoneofthefollowingcombinationofvariablesisspecified?

(a) P,θ

(b) θ,|V|

(c) |V|,δ

(d) P,Q

Q181. Whichofthefollowingquantityisassociatedwitheachbusornodeforthe

purposeofloadflowstudiesofapowersystem


(a) Realpower

(b) powerfactor

(c) Inputcurrent

(d) frequency

Q182. Thebusadmittancematrix(Ybus)ofapowersystemisnot

(a) Symmetric

(b) a squarematrix

(c) a fullmatrix

(d) generallyhavingdominantdiagonalelements

Q183. Ifavoltagecontrolledbusistreatedasloadbus,thenwhichofthefollowing limits would

beviolated?

(a) Volatge

(b) Activepower

(c) Reactivepower

(d) phaseangle

Q184. Fora15-buspowersystemwith3voltagecontrolledbus,thesizeofJacobian matrixis

(a)11X11

(b)12X12

(c)24X24

(d)28X28

Q185. Thediagonalelementsofanodaladmittancematrixarestrengthenbyadding


(a) Shuntinductances

(b) shuntcapacitances

(c) loads

(d) Generators

Q186. Theloadflowsolutionisalwaysassuredincaseof:

a. Newton-Raphsonmethod

b. Gaussmethod

c. Gauss-Seidelmethod

d. Noneofthesemethodsguarantees

Q187. Inwhichofthefollowingmethodsofloadflowanalysistheconvergenceof

solutiondoesnotdependuponchoiceofslackbus

a. Newton-Raphsonmethod

b. Gaussmethod

c. Gauss-Seidel

d. none ofthese

Q188. InaYbusmatrixthediagonalelementofeachnodeisobtainedby

a. Multiplying the admittances connected toit

b. Adding the admittances connected toit

c. Subtracting the admittances connected toit

d. None ofthese


Q189. Whichfundamentallawisappliedateachnodeinamultibussystemtoobtain Ybusmatrix

a. KVL

b. KCL

c. both

d. one of theabove

Q190. Inalargesystemof100nodes,thenon-zeroelementsmaybeassmallas a.20%

b.22%

c. 2%

d. 9%

Q191. TheBusadmittancematrixYbusis

a. Singularmatrix

b. Symmetricmatrix

c. Sparsematrix

d. All of theabove

Q192. Inloadflowstudiesofapowersystem,avoltagecontrolbusisspecifiedby

a. Realpowerandreactivepower

b. Realpowerandvoltagemagnitude

c. Voltage and voltage phaseangle

d. Reactivepowerandvoltagemagnitude

Q193. InGauss-Seidelmethodofpowerflowproblem,thenumberofiterationsmaybe

reducedifthecorrectioninvoltageateachbusismultipliedby


a. Gaussconstant

b. Acceleration constant

c. Deceleration constant

d. Blockingfactor

Q194. Loadflowstudyiscarriedoutfor

a. Faultcalculations

b. stabilitystudies

c. Systemplanning

d. Load frequencycontrol

Q195. Transientinelectriccircuitsnormallydisappearswithinatimeequalto

(a) 4 * timeconstant

(b) 2* timeconstant

(c) 8* timeconstant

(d) timeconstant

Q196. TheconvergencecharacteristicoftheNetwon–Rophsonmethodofsolvinga load flow problemis

a)quadratic b)linear

C)geometric d)cubic

Q197. Busesforloadflowstudiesareclassifiedas

1. Loadbus

2. PVbus(b)

3. Slackbus

Q 198.


Q199. Theprincipalinformationobtainedfromloadflowstudiesinapowersystemare

1. magnitudeandphaseangleofthevoltageateachbus

2. reactiveandrealpowerflowsineachofthelines

3. totalpowerlossinthenetwork

4. transientstabilitylimitofthesystem

Select the correct answer using the codes given below :

(A) 1and2

(B) 3and4

(C) 1, 2 and3

(D) 2 and4


Q200. Direction:Thefollowingtwoitemsconsistoftwostatements,onelabelledas

Assertion‘A’andtheotherlabelledasReason‘R’.Youaretoexaminethesetwo

statementscarefullyanddecideiftheAssertionAandtheReasonRareindividuallytrue

andifso,whethertheReasonisacorrectexplanationoftheAssertion.Selectyour

answerstotheseitemsusingthecodesgivenbelow.

Codes :

(A) BothAandRaretrueandRisthecorrectexplanationofA

(B) BothAandRaretruebutRisNOTthecorrectexplanationofA

(C) AistruebutRisfalse

(D) AisfalsebutRistrue

Assertion (A) : Bus admittance matrix is a sparse matrix.

Reason (R) : In load flow studies, one of the buses is take as a slack bus.

Consider the following statements in respect of load flow studies in power systems :

1. Busadmittancematrixisasparsematrix

2. Gauss-SeidelmethodispreferredoverNewton-Raphsonmethodforloadflowstudies

3. Oneofthebusesistakenasslackbusinloadflowstudies

Which of the statements given above are correct ?

(A) 1, 2 and3

(B) 1and2

(C) 1and3

(D) 2and3


101 D 121 B 141 A 161 A 181 D

102 A 122 D 142 A 162 B 182 A

103 A 123 B 143 A 163 C 183 C

104 D 124 A 144 C 164 A 184 C

105 C 125 D 145 A 165 B 185 D

106 A 126 B 146 A 166 A 186 A

107 D 127 B 147 A 167 B 187 D

108 C 128 B 148 A 168 A 188 A

109 C 129 C 149 B 169 B 189 B

110 C 130 A 150 A 170 A 190 B

111 B 131 A 151 A 171 B 191 C

112 C 132 A 152 A 172 A 192 D

113 A 133 B 153 A 173 A 193 B

114 D 134 A 154 B 174 B 194 B

115 A 135 A 155 A 175 B 195 C

116 B 136 B 156 B 176 D 196 C

117 D 137 C 157 A 177 A 197 A

118 D 138 A 158 A 178 B 198 B

119 A 139 B 159 C 179 A 199 C

120 C 140 A 160 A 180 B 200 C


Unit- 3

Q 201.

.

Q202. TheYBUSmatrixofa100-businterconnectedsystemis90%sparse.Hencethe

numberoftransmissionlinesinthesystemmustbe

(A) 450


Q204.

Q204.

Ataparticularunbalancednode,therealpowersspecified are: Leaving the

node 20 MW, 25 MW

Enteringthenode60MW,30MWThe

balancing power will be:

(a)30MWleavingthenode

(B) 500

(C) 900 (D)

1000

Q 203.

(b) 45MWleavingthenode

(c) 45 MW entering thenode

(d) 22.5MWenteringthenodeand22.5MWleavingthenode.

Q205. Thelosscoefficientsforatwo-bussystemaregivenasfollows:]

(a)B11=0.02,B22=0.05,B12=0.01,B21=0.015.

(b) B11= 0.02, B22= 0.04, B12= -0.01, B21= - 0.001.

(c)B11 = 0.03, B22= 0.005, B12= - 0.001, B2I= - 0.001.

(d) B11= 0.03, B22= 0.05, B12= 0.001, B21= - 0.001.


Q206. Foreconomicoperation,thegeneratorwithhighestpositiveincremental

transmission•losswilloperateat:

(a) Thelowestpositiveincrementalcostofproduction

(b) Thelowestnegativeincrementalcostofproduction

(c) Thehighestpositiveincrementalcostofproduction

(d) None of theabove.

Q207. Themaximumpermissiblechangeinpowerfrequencyis

(A) ±5Hz

(B) ±0.5Hz

(C) ±0.6Hz

(D) ± 0.05 Hz

Q208. automaticgenerationandvoltageregulationequipmentisinstalledoneach generator

(A) Loadfrequency

(B) Excitationvoltage

(C) BothAandB

(D) None ofthese

Q209. theytakecareofsmallchangesinloaddemand

(A) Without change in frequency andvoltage

(B) Without change in Power andvoltage

(C) WithoutchangeinRealPowerandReactivepower

(D) None ofthese


Q210. Thechangeinloaddemand,thiswillchangeinalternator

(A) Powerangle

(B) Excitationangle

(C) Firingangle

(D) None ofthese

Q211. Thechangeinloaddemand,thiswillmeetoutbyalternator

(A) Excitationvoltage

(B) Speed ofturbine

(C) BothAandB

(D) None ofthem

Q212. Thechangeinloaddemand,thiswillchangeinalternator

(A) Excitationvoltage

(B) Speed ofturbine

(C) BothAandB

(D) None ofthem

Q213.Maintainnetworkfrequencyconstantsothatthepowerssothatthepowerstation

aresatisfactorilyparallelonthesystemrunatthedesiredspeedcorrecttimeisobtained from

(A) Synchronoscope

(B) Two lampmethod

(C) Threemethod

(D) None ofthese

Q214. Poweranglewillchangeincontrolledformet


(A) MomentarilySmallchangeinspeed

(B) Large change inspeed

(C) Medium change inspeed

(D) None ofthem

Q215. powerfrequencycontrolisslowdueto

(A) turbineandgeneratormomentofinertia

(B) turbine and generatortroque

(C) turbine and generatorforce

(D) All of theabove

Q216. Changeinloaddemandcanbeidentifiedas

(A) slowvaryingchangesinmeandemand

(B) fast random variations around themean

(C) A andB

(D) None ofthem

Q217. Whatshouldbeatquestionmarkfrompicture

(A) frequency

(B) Voltage

(C) Realpower

(D) Speed

Q218. Pilot piston is usedfor

(A) Providingtohelpchangeinmainpiston

?


(B) Providing change in mainValve

(C) Providingtoflowinhydraulicoil

(D) All ofthem

Q219. These are part of LFCsystem

(A) Fly ball speedgovernor

(B) Hydraulicamplifier

(C) Linkagemechanism

(D) All ofthem

Q220. Flyballspeedgovernorisusedfor

(A) frequency

(B) Voltage

(C) Realpower

(D) Speed

Q221. This modal may namedas

(A) TurbineModel

(B) ModelofSpeedGoverningSystem

(C) generator-loadmodel

(D) All ofthem



(A) TurbineModel

(B) Model of Speed GoverningSystem


(D) All ofthem


(A) TurbineModel



(D) All ofthem

Give the answer all below questions


Q224. Thevalueatposition“1”inabovemodal

(A) ∆Pc(s)

(B) ∆PD(s)

(C) ∆PG(s)

(D) ∆F(s)


(A) ∆Pc(s)

(B) ∆PD(s)

(C) ∆PG(s)

(D) ∆F(s)


(A) ∆Pc(s)

(B) ∆YE(s)

(C) ∆PG(s)

(D) ∆F(s)


(A) ∆Pc(s)

(B) ∆PD(s)

(C) ∆PG(s)

(D) ∆F(s)


(A) ∆Pc(s)

(B) ∆PD(s)


(C) ∆PG(s)

(D) ∆F(s)

Q229. Thefinalvalueatabovemodal

(A) ∆Pc(s)

(B) ∆PD(s)

(C) ∆PG(s)

(D) ∆F(s)

Q230. Theinputvalueatabovemodal

(A) ∆Pc(s)

(B) ∆PD(s)

(C) ∆PG(s)

(D) ∆F(s)

Q231. speed regulation of thegovernor

(A) K1KC/K2

(B) K1KCK3/K4

(C) 1/K5K4

(D) none ofthem

Q232. gain of speedgovernor

(A) K1KC/K2

(B) K1KCK3/K4

(C) 1/K5K4

(D) none ofthem


R

R

R

Q233. time constant of speedgovernor

(A) K1KC/K2

(B) K1KCK3/K4

(C) 1/K5K4

(D) none ofthem

Q234. The droop slope may defineas

−1

(A) B+(1)

(B) B+(1)

(C) (1)

(D) None of them

Q235. For250MWmachinewithanoperatingloadof125MW.letthechangeinload be1%for1%

changeinfrequency(scheduledfrequency=50Hz).Then ∂P

∂ f

(A) 2.5MW/Hz

(B) 5.0MW/Hz

(C) 2.6MW/Hz

(D) 3.5MW/Hz

Q236. For250MWmachinewithanoperatingloadof125MW.letthechangeinload be1%for1%

changeinfrequency(scheduledfrequency=50Hz).Then ∂P

∂ f

(A) 0.001 puMW/Hz

(B) 0.01 puMW/Hz

(C) 0.1 puMW/Hz


(D) 1 puMW/Hz

Q237. A100MVAsynchronousgeneratoroperatesonfullloadatfrequencyof50Hz.

Theloadissuddenlyreducedto50MW.Duetotimelagingovernorsystem,thesteam

valvebeginstocloseafter0.4seconds.GivenH=5kW-sec/KVAofgeneratorcapacity.

Determinethechangeinfrequencythatoccursinthistime.

(A) 51Hz

(B) 50Hz

(C) 48Hz

(D) 49Hz




Determine Excess power input to generator

(A) 50MW

(B) 52MW

(C) 53MW

(D) 40MW




Determine Kinetic energy stored in rotating parts of generator and turbine

(A) 0.5MW

(B) 5.0MW

(C) 3.0MW

(D) 1.6MW




valve begins to close after 0.4 seconds. Given H = 5 kW-sec/KVA of generator capacity.

Determine Excess energy input to rotating parts in 0.4 sec

(A) 21000KW-Sec

(B) 20000KW-Sec

(C) 19000KW-Sec

(D) Notcalculated

Q241. Twogeneratorsrated200MWand400MWareoperatinginparallel.Thedroop

characteristicsoftheirgovernorsare4%and5%,respectivelyfromnoloadtofullload.

Assumingthatthegeneratorsareoperatingat50Hzatnoload,Assumefreegovernor

operation,howwouldaloadof600MWbesharedbetweenthem?

(A)230,370

(B)229,371

(C) 231,369

(D) Not calculated

Q242.Twogeneratorsrated200MWand400MWareoperatinginparallel.Thedroop

characteristicsoftheirgovernorsare4%and5%,respectivelyfromnoloadtofullload.

Assumingthatthegeneratorsareoperatingat50Hzatnoload,Whatwillbethesystem

frequencyatthisload?Assumefreegovernoroperation.

(A)51.59 Hz

(B) 47.69Hz

(C)48.99Hz

(D)49.00Hz

Q243. This modal isshowing

(A) 1storder LFCmodal

(B) 2ndorder LFCmodal

(C) Multiple order LFCmodal


(D) None ofthese

Q244. centraleconomicdispatchcomputerisabbreviated

(A) CEDC

(B) CEC

(C) EDC

(D) None ofthem

Q245. synchronizing coefficient is (A)

|V1||V2|

PX

(B) |V1||V2|

sin(δ0−δ0)

Pr 1 1 1

12

(C) |V1||V2|

sin(δ1−δ2) P

(D) None of them

Q246.Maintainnetworkfrequencyconstantsothatthepowerssothatthepowerstation

aresatisfactorilyparallelonthesystemrunatthedesiredspeedcorrecttimeisobtained from

(A) Synchronoscope

(B) Two lampmethod

(C) Threemethod

(D) None ofthese

Q247. Poweranglewillchangeincontrolledformat

(A) MomentarilySmallchangeinspeed

(B) Large change inspeed

(C) Medium change inspeed

X


(D) None ofthem

Q248. powerfrequencycontrolisslowdueto

(A) turbineandgeneratormomentofinertia

(B) turbine and generatortroque

(C) turbine and generatorforce

(D) All of theabove

Q249. Two area controlmeans

(A) One power system areinvolved

(B) twoormorepowersystemareinvolved

(C) A andB

(D) None ofthem

Q250. Thisequationshows Ksg

1+Tsgs

(A) TurbineModel



(D) All ofthem

Q251. Thisequationshows Kt

1+T ts

(A) TurbineModel



(D) All ofthem

Q252. Thisequationshows Kps

1+T pss


(A) TurbineModel



(D) All ofthem

201 D 221 B 241 C

202 C 222 A 242 B

203 C 223 C 243 A

204 B 224 B 244 A

205 C 225 A 245 B

206 A 226 B 246 A

207 B 227 C 247 A

208 C 228 D 248 A

209 A 229 D 249 B

210 A 230 A 250 C

211 C 231 B 251 C

212 C 232 B 252 C


213 A 233 C

214 A 234 A

215 A 235 A

216 C 236 B

217 A 237 A

218 D 238 A

219 D 239 A

220 A 240 B


Unit=4

Q253. Zeropowerfactormethodofanalternatorisusedtofindits

(A) fieldresistance

(B) armatureresistance

(C) efficiency

(D) voltageregulation

Q254. Thepowerfactorofanalternatorisobtainedfromits

(A) excitation

(B) speed

(C) load

(D) noneoftheabove

Q255. Forparalleloperation,alternatorsmusthave

(A) samespeed

(B) same kvarating

(C) same voltagerating

(D) none of theabove

Q256. Foralternationhavingfractionalpitchof5/6thecoilspanis

(A) 90°

(B) 120°

(C) 150°

(D) 180°

Q257. Fractionalpitchtoeliminate7thharmonicfromalternatoremfis

(A)7/6

(B)6/7

(C)6/5

(D)3/5


Q 258.Consider the following statements about a three-phase synchronous generator

synchronizedtoaninfinitebuswhenitsmechanicalinputisincreasedgraduallywith field current

heldconstant:

1 Thepowerfactorofthecurrentsuppliedbecomesmorelagging

2 Thepowerfactorofthecurrentsuppliedimproves

3 The power factor remainsunity

4 Theloadangleisincreased Of

thesestatements

(A) 1 alone iscorrect

(B) 2 alone iscorrect

(C) 2and4arecorrect

(D) 3and4arecorrect

Q259. A 3-phase synchronous generator, with its armature resistance and the leakage

reactancebeingneglected,issynchronizedtoaninfinitebusanditsfieldexcitationis keptconstantthereafter

NowthemachineisloadedbySupplyingmechanicalinput totheshaftsothattheload-

angleδreachesavalueof60°Underthiscondition,the operating power-factor wouldbe

(A) 0.866leading

(B) 0.866lagging

(C) 0 .5leading

(D) 0.5lagging

Q260.Aroundrotorsynchronousgeneratorhasaleakagereactanceof10%,armature

reactionreactanceof90%andnegligiblearmatureresistancewiththemachineinitially

runningatratedspeedandterminalvoltageof1.0pu,a3-phaseshort-circuitisapplied

Thesustainedarmaturecurrentwillbe

(A) 1.25pu

(B) 1.11pu

(C) 1.0pu

(D) 0.9pu

Q261. Followingasuddenshort-circuitattheterminalsofa3-phaseunloaded

synchronousgenerator,theinitialeffectofthepole-facedamperwindings,isto


(A) establishthearmaturefluxthroughthedirect-axismagneticcircuitofthe machine

(B) allowonlypartiallinkageofthearmaturefluxwiththemainfieldwinding

(C) confinethearmaturefluxtocompletelylinkthedamperwinding

(D) repelthearmaturefluxandconfineittotheleakagefluxpathintheair-gap Q262.

Inasynchronousgeneratoroperatingatzeropflagging,theeffectofarmature

reaction is

(A) magnetizing

(B) demagnetizing

(C) cross-magnetizing

(D) both magnetizing andcross-magnetizing

Q263. Whichofthefollowinglimitthereactivepoweroutputofasynchronous generator?

1 Armaturecurrent

2 Fieldcurrent

3 Loadangle

4 Prime moverinput

Select the correct answer using the codes given below:

Codes

(A) 1 and2

(B) 2and3

(C) 3and4

(D) 1and4

Q264. Thesteady-statestabilitylimitofasynchronousgeneratorcanbeincreasedby

(A) an increase in itsreactance

(B) anincreaseintheexcitationofthemachine

(C) adecreaseinthemomentofinertiaofthemachine

(D) anincreaseinthemomentofintertiaofthemachine

StatewhetherthefollowingstatementsrelatedtoSynchronousGeneratoraretrue(T)or false(F):


Q265. Synchronousreactancecanbedeterminedfromopencircuitandshortcircuittests

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q266. Voltageregulationcanbedeterminedbysynchronousimpedancemethod

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q267. Percentageresistanceistheresistancedropatratedcurrentandfrequency

expressedasthepercentageoftheratedvoltage

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q268. MMFmethodforregulationdoesnotusedataavailablefromopencircuitand short circuittests

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q269. Inshort-pitchwindingsfractionalnumberofslotsperpolecanbeused

(A) TRUE

(B) FALSE


(C) NotPossible

(D) None ofthese

Q270. Oneoftheadvantageofshortpitchwindingsissavingincopper

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q271. Largescalepowergenerationisdonebysynchronousgenerators

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q272. TheanglebetweenEgandVtiscalledthepowerangle

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q273. Synchronousreactanceisdeterminedbysynchronousreactancemethod

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q274. Synchronousgeneratormustoperateatthecorrectspeedasitdeterminesthe

frequencysincethenumberofpolesisfixedforanygivenmachine


(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q275. Thevoltageregulationofanacgeneratorisdefinedastheriseinvoltagewhen

theloadisreducedfromfull-ratedloadvaluetozero,speedandfieldcurrentremaining constant

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q276. Armaturereactioninanalternatoraffectsgeneratedvoltage/phase

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q277. Armaturereactioninanalternatorismagnetizingatlaggingloads

(A) TRUE

(B) FALSE

(C) NotPossible

(D) None ofthese

Q278. Maximumdemandonapowerplantis

(A) Thegreatestofall"shorttimeintervalaveraged"demandduringaperiod

(B) InstantaneousmaximumvalueofKVAsuppliedduringaperiod


(C) Both (a) or(b)


Q279. Inanalternator,thefrequencyperrevolutionisequalto

(A) Number ofpoles

(B) Number of pairs ofpoles

(C) Number of armatureconductors

(D) Forty

Q280. Squirrelcagebarsplacedintherotorpolefacesofanalternatorhelpreduce hunting

(A) Above synchronous speedonly

(B) Below synchronous speedonly

(C) Aboveandbelowsynchronousspeedsboth


Q281. Stationaryalternatorshouldnotbeconnectedtolivebus-barsbecauseit

(A) Islikelytorunassynchronousmotor

(B) Willgetshort–circuited

(C) Willdecreasebus-barvoltagethoughmomentarily

(D) Willdisturbgeneratedemf'sofotheralternatorsconnectedinparallel

Q282. Withaunityloadp f,theeffectofarmaturereactiononthemainfieldflux of an

alternatoris

(A) Distortional

(B) Magnetizing

(C) Demagnetizing

(D) Nominal


Q283. Atlaggingloads,armaturereactioninanalternatoris

(A) Cross-magnetising

(B) Demagnetizing

(C) Non-effective

(D) Magnetizing

Q284. Thefrequencyofvoltagegeneratedbyanalternatorhaving4polesandrotatingat 1800 rpmis

(A) 60Hz

(B) 7200Hz

(C) 120Hz

(D) 450Hz

Q285. Themaindisadvantagesofusingshortpitchwindinginalternatorsisthatit

(A) Reducesharmonicsinthegeneratedvoltage

(B) Reducesthetotalvoltagearoundthearmaturecoils

(C) Producesasymmetryinthethreephasewindings

(D) IncreasesCuofendconnections


(A) Efficiency

(B) Voltageregulation

(C) Armatureresistance

(D) Synchronousimpedance

Q287. Armaturereactioninanalternatormainlyaffects

(A) Rotorspeed


(B) Terminal voltage perphase

(C) Frequency ofarmaturecurrent

(D) Generated voltage perphase

Q288. Theeffectofincreasingairgaplengthintheinductionmotorwillincreasethe

(A) Powerfactor

(B) Speed

(C) Magnetizingcurrent

(D) Air gapflux

Q289. Theprincipleofoperationofa3phaseinductionmotorismostsimilartothatofa

(A) Synchronousmotor

(B) Repulsion start inductionmotor

(C) Transformerwithashortedsecondary

(D) Capacitor start, induction runmotor

Q290. Squirrelcagebarsplacedintherotorpolefacesofanalternatorhelpreduce hunting

(A) Above synchronous speedonly

(B) Below synchronous speedonly

(C) Aboveandbelowsynchronousspeedsboth


Q291. Thestationaryalternatorshouldnotbeconnectedtolivebus-barsbecauseit

(A) Islikelytorunassynchronousmotor

(B) Willgetshort–circuited

(C) Willdecreasebus-barvoltagethoughmomentarily


(D) Willdisturbgeneratedemf'sofotheralternatorsconnectedinparallel

Q292. Withaunityloadpf,theeffectofarmaturereactiononthemainfieldfluxofan alternatoris

(A) Distortional

(B) Magnetizing

(C) Demagnetizing

(D) Nominal

Q293. Atlaggingloads,armaturereactioninanalternatoris

(A) Cross-magnetising

(B) Demagnetizing

(C) Non-effective

(D) Magnetizing

Q294. Thefrequencyofvoltagegeneratedbyanalternatorhaving4polesandrotatingat 1800 rpmis

(A) 60Hz

(B) 7200 Hz

(C) 120Hz

(D) 450Hz

Q295. Themaindisadvantagesofusingshortpitchwindinginalternatorsisthatit

(A) Reducesharmonicsinthegeneratedvoltage

(B) Reducesthetotalvoltagearoundthearmaturecoils

(C) Producesasymmetryinthethreephasewindings

(D) IncreasesCuofendconnections



(A) Efficiency

(B) Voltageregulation

(C) Armatureresistance

(D) Synchronousimpedance

Q297. Armaturereactioninanalternatormainlyaffects

(A) Rotorspeed

(B) Terminal voltage perphase

(C) Frequency ofarmaturecurrent

(D) Generated voltage perphase

Q298. Theeffectofincreasingairgaplengthintheinductionmotorwillincreasethe

(A) Powerfactor

(B) Speed

(C) Magnetizingcurrent

(D) Air gapflux

Q299. Theprincipleofoperationofa3phaseinductionmotorismostsimilartothatofa

(A) Synchronousmotor

(B) Repulsion start inductionmotor

(C) Transformerwithashortedsecondary

(D) Capacitor start, induction runmotor

Q300. Twoalternatorsareparalleled

(A) So that one isn'toverworked


(B) Becauseofarisingloaddemand

(C) To ease the workload

(D) Becauseofthedecliningloaddemand


253 D 273 A 293 D

254 C 274 A 294 A

255 C 275 A 295 B

256 C 276 A 296 B

257 B 277 B 297 D

258 B 278 A 298 C

259 B 279 A 299 C

260 B 280 C 300 B

261 B 281 B

262 B 282 A

263 B 283 D

264 B 284 A

265 A 285 B

266 A 286 B

267 A 287 D

268 B 288 C

269 A 289 C

270 A 290 C

271 A 291 B

272 A 292 A


ELECTRICAL MACHINE-1 –(3140913)

GUIDED BY: PROF. RUSHIKESH V. PANDYA

Date post:	02-Sep-2021
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