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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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%
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
FourloadsasshowninfiguregivenbelowareconnectedtoapowerstationAbsciseistimefrom
0to24hrsinallcases,OrdinaterepresentstheloadinKW
Q10. Whichloadhasthelowestaveragedemand?
LoadA
LoadB
LoadC
LoadD
Q11. Whichloadsoffertheidenticalaverageload?
(A) AandB
(B) BandC
(C) CandD
(D) A, B andD
Q12. Thepeakloadontheplantis
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
Gi Gi Gi
Q16. Pmin≤P≤Pmax,i=1,2,…….,
(A) Real Power balanceconstraints
(B) Generation capacity constraint
(C) Both A andB
(D) None ofthem
Q17. Sli≤ Smaxli, i = 1, ...,NL
(A) Real Power balanceconstraints
(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
(A) Real Power balanceconstraints
(B) Generation capacity constraint
(C) Security constraints
(D) None ofthem
Q19. Followingpowerplanthasinstantstarting
(A) nuclear powerplant
(B) hydro powerplant
(C) diesel powerplant
(D) both (b) and(c)
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Questions 45 to 48 refer to the data given below:
ManufacturerAoffershisequipmentcostingRs150,000+45xKW the equipmentis
guaranteedtogivethefollowingoperatingcostRs18+0.007KWh
ManufacturerBoffershisequipmentcostingRs1,12000+50xKWTheoperatingcostis guaranteed as Rs 16.50 +
0.0072KWh
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
(D) all of theabove.
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
Unit -2
Q101. Load curve helps indeciding
(A) Sizes of the generationunits
(B) Totalinstalledcapacityoftheplant
(C) Operating schedule of generatingunits
(D) all of theabove.
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(D) Gas turbineplant
Q110.Aconsumertakesasteadyloadof200kWatapowerfactorof0.85laggingfor8
hoursperdayand315daysperannum.TheannualpaymentunderthetariffofRs80per
annumperkAplus10centsperkWhwillbe
(A) Rs 5040 (B)
Rs 50,400 (C) Rs
69,200 (D)
Rs88,400
Questions 111 to 115 refer to the data given below:
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
Unit- 3
Q 201.
.
Q202. TheYBUSmatrixofa100-businterconnectedsystemis90%sparse.Hencethe
numberoftransmissionlinesinthesystemmustbe
(A) 450
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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.
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
?
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Q222. This modal may namedas
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(A) TurbineModel
(B) Model of Speed GoverningSystem
(C) generator-loadmodel
(D) All ofthem
Q223. This modal may namedas
(A) TurbineModel
(B) Model of Speed GoverningSystem
(C) generator-loadmodel
(D) All ofthem
Give the answer all below questions
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
Q224. Thevalueatposition“1”inabovemodal
(A) ∆Pc(s)
(B) ∆PD(s)
(C) ∆PG(s)
(D) ∆F(s)
Q225. Thevalueatposition“2”inabovemodal
(A) ∆Pc(s)
(B) ∆PD(s)
(C) ∆PG(s)
(D) ∆F(s)
Q226. Thevalueatposition“3”inabovemodal
(A) ∆Pc(s)
(B) ∆YE(s)
(C) ∆PG(s)
(D) ∆F(s)
Q227. Thevalueatposition“4”inabovemodal
(A) ∆Pc(s)
(B) ∆PD(s)
(C) ∆PG(s)
(D) ∆F(s)
Q228. Thevalueatposition“6”inabovemodal
(A) ∆Pc(s)
(B) ∆PD(s)
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(D) 1 puMW/Hz
Q237. A100MVAsynchronousgeneratoroperatesonfullloadatfrequencyof50Hz.
Theloadissuddenlyreducedto50MW.Duetotimelagingovernorsystem,thesteam
valvebeginstocloseafter0.4seconds.GivenH=5kW-sec/KVAofgeneratorcapacity.
Determinethechangeinfrequencythatoccursinthistime.
(A) 51Hz
(B) 50Hz
(C) 48Hz
(D) 49Hz
Q238. A100MVAsynchronousgeneratoroperatesonfullloadatfrequencyof50Hz.
Theloadissuddenlyreducedto50MW.Duetotimelagingovernorsystem,thesteam
valvebeginstocloseafter0.4seconds.GivenH=5kW-sec/KVAofgeneratorcapacity.
Determine Excess power input to generator
(A) 50MW
(B) 52MW
(C) 53MW
(D) 40MW
Q239. A100MVAsynchronousgeneratoroperatesonfullloadatfrequencyof50Hz.
Theloadissuddenlyreducedto50MW.Duetotimelagingovernorsystem,thesteam
valvebeginstocloseafter0.4seconds.GivenH=5kW-sec/KVAofgeneratorcapacity.
Determine Kinetic energy stored in rotating parts of generator and turbine
(A) 0.5MW
(B) 5.0MW
(C) 3.0MW
(D) 1.6MW
Q240. A100MVAsynchronousgeneratoroperatesonfullloadatfrequencyof50Hz.
Theloadissuddenlyreducedto50MW.Duetotimelagingovernorsystem,thesteam
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
(B) Model of Speed GoverningSystem
(C) generator-loadmodel
(D) All ofthem
Q251. Thisequationshows Kt
1+T ts
(A) TurbineModel
(B) Model of Speed GoverningSystem
(C) generator-loadmodel
(D) All ofthem
Q252. Thisequationshows Kps
1+T pss
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(A) TurbineModel
(B) Model of Speed GoverningSystem
(C) generator-loadmodel
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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):
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(C) Both (a) or(b)
(D) None of theabove
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
(D) None of theabove
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Q286. Zeropowerfactormethodofanalternatorisusedtofindits
(A) Efficiency
(B) Voltageregulation
(C) Armatureresistance
(D) Synchronousimpedance
Q287. Armaturereactioninanalternatormainlyaffects
(A) Rotorspeed
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
(D) None of theabove
Q291. Thestationaryalternatorshouldnotbeconnectedtolivebus-barsbecauseit
(A) Islikelytorunassynchronousmotor
(B) Willgetshort–circuited
(C) Willdecreasebus-barvoltagethoughmomentarily
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Q296. Zeropowerfactormethodofanalternatorisusedtofindits
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
(B) Becauseofarisingloaddemand
(C) To ease the workload
(D) Becauseofthedecliningloaddemand
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
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
Faculty of Degree Engineering - 083 Department of Electrical Engineering -09
ELECTRICAL MACHINE-1 –(3140913)
GUIDED BY: PROF. RUSHIKESH V. PANDYA