3309/1 (N) March 2023 : 845 INTRODUCTION TO ELECTRIC GENERATION SYSTEMS: Time Allowed: 2.8 Hows Full Marks: 60 Answer to Question No. 1 of Group A is compulsory and to be answered first. This answer Is to be ‘made In keparate loose script(s) provided for the purpose. Maximum time allowed is 30 minutes, after which the loose anewer scripts will be collected and fresh answer scripts for answering the remaining part ‘ofthe question wil be provided. On early submisslon of answer seripts of Quertion No.1. student will feet the remaining script earlier. Answer any Five (08) Questions from Group B, Group A 1. Choone the carrect answer from the given alternatives (any twenty): 1320 J. Beonomizer is used to heat 8) Air peed water c) Flue pases d) All above. \\z fi, The famction of the moderator in a nuclear power plant is to (a) Stop chain reaction, (b) Absorb neutrons, (c)Reduce the speed of neutrons, (d) Reduce temperature. A. iii, __takes water from valve house to turbine in hydroelectric power plants. (a) Spillway, PSV Penstock, (c) Fore bay, (d) Tail race. For Flue gas flow, tick thecorrect sequence. 2) Boiler-Air preheater - economizer- ID fan-Chimney, b) Boiler-ID fan -Air preheater-Economizer- Chimney, c) Boiler - Economizer- Air preheater- ID fan-Chimney, d) None of the above. 5a Induced draft fans are used to ‘8) Cool the steam let out by the turbine in thethermal power station, Wool the hot gases coming out of boiler, c) Forces the air inside the coal furnace, d) Pull the gases out of furnace. vi. Function of Deserator is 4) Heat the water, b) Heat the air in the water, ¢) Remove dissolved gases in the water,d) None of these. Load factor of « power station is defined as { () Maximum demand/average load, (b) Average load/connected load, (p¥“Average load/maximum : ‘demand, (d) connected load/Average load. vill. Steam turbine works onthe principle of __eyele. ¥ 4) Carmot,b) Brayton, ef Rankine, &) None ofthe above “The funtion of a surge tank is (a) To supply water at constant pressure (b) To produce surges in the pipe line «J To relieve water hhammer pressures in the penstock pipe (d) To control water flow in turbine. Sf The thermal eisiency ofa steam power station is a) 38% b) 28% c)40% 4) 45% The nuclear energy is measured in (a) MW, (b) Farad, (c) Curie (d) MeV. © scanned with OKEN Scannerxii Pp Xi xxii wail xxv. Which of the following is base load power station? I. Hydroelectric, 2. Diesel, 3. Thermal, 4. Pumpeg storage. $4 Only 1,2,3, (b) Only 4, (c) Only 1,3, (d) Only 1.4. If maximum demand of a power plant is equal to the plant capacity then lant reserve capacity will be zero, (b) Diversity factor will be unity, (c) Load factor will be unity, (d) Load factor will be nearly 60% The frst nuclear power plant in India is built at (a) Kota, (b) Kalapakkam, (o} Tarapur, (4) Baraclly. Flat rate tariff is charged on the basis of (@) Connected load, (5 Units consumed, (e) Maximum demand, (4) Both (a) and The cheapest plant inoperation and maintenance is 2) Thermal power plant, b)Nuclear power plant, c} lydropower plant, d) Diesel engine power plant. The following element isa fissile materia 2)238Upf235U)232THA) 240Pu. Control rod of @ nuclear power plant is made of _2)Copper.b) Graphite, c) Boron,d) Silicon. ‘The value of demand factor is _2)Léss than one, b) Equal to one, c) Greater than one, d) Greater than two. ‘The gas turbine power plant mainly uses which among the following fuels? : 2) Wood by Natural gas and liquid petroleum fuel c) Coal and Peat d) Biogas Francis and Kaplan turbines are used for__heads. (a) High, (b) High and Medium, (c) Low, (d) Low and Medium In an interconnected grid system, the diversity factor of the whole system 2) increases, b) decreases, ¢) remains constant, d) depends on the load ‘The area under the daily load curve gives ‘a) average load, b) maximum demand, c) units generated, d) connected load Fixed charge in tariff is 42) Cost of investment irrespective of energy generated, b) Operating cost of the fuel along with cost of investment plant, c) Cost of fuel only, d) None of the above. ‘The most ideal tariff for the consumer is 9) Two par tariff, b) Three part tariff, c) Both (a) and (b), d) None ofthe above. Group B 1) Write the points to be considered for selection of site of coal based Thermal Power Plans. b) Write the functions of Economiser and Electrostatic precipitato. as) 8) Write the differences between fission and fusion reaction. b) What are the different types of nuclear reactors used in nuclear power plant? ©) Briefly explain the main components of a nuclear reactor. (25#1.5+4) 2 © scanned with OKEN Scannera) Briefly explain the working of large hydro power plant with the help ofa proper layout, ¥) Whats the function of Pump storage plants? (622) a) Write the meritsand demeritsof Hydro Electric Power Plants. ¥) A Hydro station has a mean head of $0 m and is supplied from a reservoir at a rate of 10 m’ per second. Calculate the power generated in kW if the efficiency of the power plant is 80%. Assume the density of water 1000 kg/m’, (4+4) a) Write the merits and demerits of Diesel Electric Power Plant. b) Explain the working of Gas turbine power plant with the help of block diagram. GH) 7. a) Define the following terms, i) Demand factor, i) Load factor, ii) Diversity Factor. b) The load on a power plant on a typical day is as follows, Time 12AM-6 AM | 6AM-9AM. 9AM-6PM SPM-10PM | 10PM-124M Load(MW)] 25 50 90 120 25 Plot the load curve and load duration curve of the power plant, Also find the load factor of the power plant. : os) 8. a) What information are conveyed by a load curve? b) Write a short Note on Integrated Load Duration Curve. (44) 9, a) What are the advantages of interconnected power system? (44) ») Briefly explain two-part tariff © scanned with OKEN Scanner30972(N) Mareh 2023 843 * ELECTRICAL CIRCUITS Time Allowed: 2.5 Hours Full Marks: 60 to Question No, 1 of Group A fs compulsory and to be answered first. This answer is to be made in separate loose script(s) provided for the purpose. Maximum time allowed fs 30 minutes, after which the loose answer scripts will be collected and fresh answer scripts for answering the remaining part of the {question will be provided. On early submission of answer scripts of Question No. 1, a student will get the remaining script earller. Answer any Five (05) Questlons from Group B. Group A 1. Choose the correct answer from the given alternatives (any twenty): 1x20 i) What is Kirchhoff's voltage law (KVL)? Nay The sum of the voltages in a closed loop is equal to zero. 'b) The sum of the currents entering a node is equal to the sum of the currents leaving the node c) The sum of the resistances in a closed loop is equal to zero. ) The sum of the conductance in a closed loop is equal to zero ii) na series circuit, the current is ay The same at all points in the circuit ’) Different at different points in the circuit €) Zero at ll points inthe circuit ) 4) Cannot be determiied iii) What is the power dissipated by a 20 ohm resistor with a current of 2 A flowing through it? 20W yb)aoW <8 W ) 160 W iv) The product of rms values of current and voltage is called as 2) Real power pf Apparent power ¢) Reactive power 4) Polar curves ¥) The Power factor of pure inductive load circuit is a)unity pf b)Zeropf lagging LgyZeropfleading 4) All ofthese vi) The Power Factor for resonance circuit is YW) unity pf “b)Zero pflaggingyj- ©) Zero pfleading _d) All of these vii) Form factor of pure sine wave is { a)132 \pyrap ot a1.92 viii) Dhe reciprocal of resistance is called 1 \s)Conductance¥? —b) Susceptance ¢) Impedance d) Admittance ix) Derivative of a st inction is a function \ a) ramp Sialic c)doublet —_d) Parabolic x) Intaynal rgsistance of an ideal voltage pource a 1 990 \oyintinity? —_) 1000 i ofthe above xi) The series Resonance-eircuit having R=2.0, L=1 mH & C= 0.1,F. The value of Q = _ SSR Y © scanned with OKEN Scanneri 7 sis__— rated voltage xii) Ina thre pase AC Eien the sum of al Sra ofthe above } sbintinite co) NS (ty) )One (1) igeuit efficiency of ii) Maximum power transfers at cite a) 100% \by50% ‘is a) 15%\S snare per el 10 tom xiv) Fora polyphase system, the number of Wattmeter req! red t0 8) Number of wires 1 {\b)One tess than numberof wires (> ‘c) Number of phases + @None ofthe above x0) Ina three phase, delta connection — a)line current is equal to phase currenty ine voltage is equal to phase voltage ©)None of the above ‘Line voltage and line current is zer0 xvi) A circuit having neither an emf source nor any energy source is known as a) Linear ei ') Unilateral circuit tral circuit \ \Srtasne sat n xvii) The Unit of Reactive Power is \aKW wxvayy — Axykvar KW-Hr vii) Ina detaconnectd load the relation between in voltage andthe phase voltage is? 2) line voltage > phase voltage FD ») line voltage = phase voltage xix) Transient response analysis is done for syste 8) Unstable | Stable ©) Conditionally stable 4) Marginally stable 2x4) Sundard test signals in Transient response ‘Dimple signal “ 'b) Ramp signal ©) Unit step signal \ AYA of the mentioned sui) The Laplace transform ofthe signal u(t) is aus Y-IS foes a sai) Laplace transform analysis gives 2) time domain response only Dyequency domain response oaly ‘c) both (a) & (by 6) real response only © scanned with OKEN ScannerNt 1 xxiii) Energy stored in a coil having inductance 1H1 and current flowing through it 2 emp is ont b)4 Joule —c)2 Joule —d) I Joule xxiv) Condition of symmetry in Z-parameter representation is 8) Zy=2n Yn z; ©)2Zn~ Zn d)None of these xxv) Condition of symmetry in ABCD parameter representation is a) AD-BC=1 b)BeD o) AC dA=D e Group B a ‘@) What is the difference between mesh and loop? 1) Find the current in each branch of the following circuit using Nodal Analysis. (2+6) “9 | Ay e4~ ' | 3. a) State Superposition theorem, >) Find the value of Rg, Re, Re in the following star circuit +6) anioa reo — nee 4, a) Find out the Q factor of series Resonating circuit b) Find the resonance frequency for series R-L-C circuit a4) 5. A balanced delta connected load, consisting of three coils, draws 10V3 A at 0.5 power etn from 100 V, 3.phase supply Ifthe coils ae re-connectd instar across the same Supply, find the line current and total power consumed ® way 6. a)What do you mean by Transmission parameters? ») Derive “open circuit parameters” of the following circuit. eo © scanned with OKEN Scanner(4+4) 7. a)State and Prove final value theorem, (s+4) §) Find the Laplace transform ofthe expression: Bane the relationship between phase vo input power toa 3-phase Star networ 400V and 864 respectively, age and line voltage in 3-phase star connected system. onaitnred as SKW. Ifthe voltage and current to the system are determine the power factor of the system? (5+3) th switch i ir wil Postion 1. Find eurent (for ©0ifthe switch is 8 (2+6) - al f ww ohm oan @ scanned with OKEN ScannerMarch 2023 : 69 ELECTRICAL AND ELECTRONIC MEASUREMENT er is to be after which Alc compulsory and to he answered first. Thi ed is 30 mi rial used in a spring control device should have the following property ‘magnetic ).Most be of low temperature co-efficient ¢) Should have low specific system and enables the latter to reach its final 'b) Controlling device -FADampingdevice _d) All ofthese pre “Theuse of which typeof instruments are merely confined within laboratories as standardizing instruments? \AiAbsolute —_b) Indicating epecording 4) Integrating ge for a given measuring system is referred to as- d) none of these. psign of range of instrument generally made of — ‘byfanganese, c)nichrome, d) aluminium. vi, Meter constant Ofenergy meter agen by: a)rewkw Yzew/kwhr,c) kwitevSd) Kwhrirev. ‘vi, The minimyatfrno of wattmeter required to measure power of 3 phase unbalanced star connected load is- 1 jon, vo, thre, four Difference between the true value and measured value is called- ajaccuracy, precision, or, _d) sensitivity. jx. _A-wheatstone bridge cannot be used for precision measurement because eror is ed on account of above. ffinermo ‘lectric emf, b) resistance of connecting lead, c) contact resistance) alf ofthe p dof transformer? x. CTs basically a tep-up —_¢) Isolation fone ofthese iplexer @ scanned with OKEN Scannerxiii, xiv. A Tna single phase power factor meter the A.C. voltages only } type of in b\Volage ie two. phase difeence between he currents in the tw p 90" pSlAnprox oot bY Approx 0” C0) Exe be used CRO, can be used to pease 7 «Frequency Ay Any af the above xx. For measuring a very high resistance we should use | aKetvins double bridge b) Wheat stone bridget} Megat d) None of these xvi. In which instrument creeping can be observed? a)Voltmeter b) Ammeter c) Wattmeteyy Energy meter xvii, xviii, xxi xxiv. Which ofthe following are integrating instruments? eter nergy meter The power of gephase circuit can be measured by using a minimum of. number of wattmeters, i a 3) nbfi+ ke} d) 20 Capacitor can be measured by: a)Kelvin Double Bridge bf Wheatstone Bridgt-ef Schering Bridge d) Maxwell Bridge In a Kelvin's double bridge two sets of readings are taken when measuring a low resistance, one with the direction of current reversed. This is done to- nce. tb) eliminate the effect of resistance of leads, ‘rrect for te the effect of thermo-clectric emis, a)eliminate the effect of con ‘changes in battery voltage) CT has two types of error, these are phase angle error and- fWerecpingerror _—b) parallaxerror—_—_c) atio error Lay one ofthese ‘A permanent magnet is used in ~ 1) PMMC instrument b) instrument 6) EMMCinsieument&) CRO messed wth he help oan ammeter rand a voimee, by the product of readings of two instru a sumof power cnsned by lost nd the ammeter, d) none of the above, ” as Ny B)DC.voliages only 6) Frequency &) Any of ressure coils is @ scanned with OKEN Scanner10. 8)Draw the neat labeled diagram the con a) Two wattmeters. Group B ing instrument? What is critical damping? (543) Precision and Accuracy, ed? Give in brief the diferent methods of damping. B45) ‘operation DJA moving coil instrumer can be used to measure v ion of moving iron repulsion type instrument and explain its nt has a resistance of 100 and gives full scale deflection of ImA. Sho ‘oltage up to 250 volt, Are connected to measure the power consumed by a 3-phase load with power 0.4Total power consumed by the load, as indicated by the two wattmeters is 30 kW. Find the readings, Power factor wattmeter has a current range ofS amp and voltage range of 200 vot If the fll scale deflection is 500 watt, what should be the value of Multiplying Factor? (#3) 8) What is creeping error? How can it be overcome? ) Mention the differen erors which oceur in dynamometer type wattmeter (a4) 1) Derive the equations ‘of balance for an Anderson's bridge. ) Write down two differences between C.T and PT instrument. (642) a) Draw the block diagram of a basic CRO. 'b) What are major components of a CRT? aH) ‘What are the functions ofa spring in P.M.M.C instrument? (62) Draw the block diagram of a basic Digital Frequency Meter and write the function of each block. 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(sy Sanh at oy Cate Compr pF rtretly Cops @ scanned with OKEN Scanner: aimee | I condoctvly (Q} both inductively & conductvely (4) neither inductively nor conductively xxiv, The most suitable connection for 3 phase 4 wire s (a) delta-delta(Wpstar-star (c) star-delta (d) dela-star xxv, As compared to A- A bank, the capacity of V-V bank of transformers is___% (87.7 (0) 66.7 (6) 86.6 (50, 5 “ 250 V. it has armature resistance resistance 0.04 0, brush drop 1 volt per brush. 100 9, series field ‘Watt, Find the generated EMF. @ scanned with OKEN Scanner@) 1 Q) following date on 0.C, & S.C. tex 1 the magnetizing component of No Load (6) (4) Q) Q) Sie Of single phase transformer loaded with ress ive-inductive load (4) ta nsformer is built on a core of effective cross sectional rea 250 a8 wide, Find the number of tums on the high voltage side and (4) (4+4=8) ransformer, ee phase transformer, @ scanned with OKEN Scanner30915 (N) March 2023 : ANALOG & DIGITAL ELECTRONICS 835 towed Full Marks: 60 answer to Question No, 1 of G separate een Ais compulsory and to be answered fest, This answer Isto be made fo scart me sei) re forthe pares Naima he owed i. 20 sninute, after which the loose provided. On rl lected ad fresh anwer seripts for answering the remaining part of the question wit |. On carly submission of answer scripts of Question No. 1, a student will get the remalalng seript cattle. Answer any Five (08) Questions from Group 1b Group A | 1. Choose the correct answer from the given alternatives (any twenty): 20x1°20 4) Ripple frequency of the output waveform of a full-wave reetifier when fed with a5Ol1z sine wave is ph 25H, 8) SOHz ) 100K €) 20012 “ET is increased, its drain curret ii) When the positive voltage on the gate ofa p-channel 2) imereases, b) decreases ) remains the same, dj pone of the dove diy One condition for oscillation is -a)a phase shift around the Feedback loop of 180°, b)a gain around the feedback Toop of ene third, c)a phase shift around the feedback loop ‘of O'd)a gain around the feedback loop of less than | y iy) PIV fora diode ina Bridge Rectifier -(0)V a 0}2V (©) Vul2, (d) Vin 4 4) The ratio of Tee i called {0) Alpha (by,Beta (c) Gamma (@) None of the above i) Ifthe maximum collector current due to signal alone fs 3mA, then 2e10 signal collector current should be atleast {qual to=~a) 6m b) 1-SmA )3mA , d) LA. vii) MOSFET is a device {a Voltage controlled (6) Current controlled, (c) both, (f} none of the above viii) Which part of the transistor is heavily doped? (a) Emit, b Base, €) Collector, (8) Allare equally doped. jx) How many terminals are there in UIT? a1 M203 D4 transistor represents) Values of lc and Ve when signal is applied, b)The magnitude ofthe x) Operating point o signal, Zero signal values of Leamd Ver 4) none of the above. xi) MOSFET Stands for - (a) Metal Oxide semi conductor field effect transistor (b) Modern oxide silicon field effect transistor (@) Metal oxide ‘semi conductor forced effect transistor (4) none of the above ate : © scanned with OKEN Scanner010, ©1001, 490011 xxii) Which of the following 4-bit BCD combination is invalid? — a010l, ») gate y AND gate (c) NOT jrcuit is (a) OR xiii) The inputs of n NAND gate are connected together. ‘The resulted circuit I (a) Ol te (d) None of the above ND gate, (b) OR gate, (c) AND gate, & None of the above. 1, K-—0,(c)J-0, Kel, (@) Jol, Kat , + bat inputs LOW is (a) EX-NOR gate , xiv) The universal gate is (a) » 0) How is aK Flip-op made to toge! (9) 1-0, K=O. B) 1" xvi) A logic circuit that provides a HIGH output for both inputs HIGH o' (b) OR gate, (c) EX-OR gate, (d) NAND gate vii) Which typeof gate can be used to add two bits (g) EX-OR, (0) BRNOR, (©) NAND, (4) NOR xvii) How many flip-flops are required to make MOD-10 counter? (a) 1 (H)?2 (©) 3and (d) 4. xix) Why is a demultiplexer called a data distributor? «) The input wil be distributed to one ofthe outputs b) One ofthe inputs will be selected for the output c) The cvtput will be distributed to one ofthe inputs gj Single input to Single Output . xx) What is the main role of an ADC? . 2) Amplify, b) Conver analog signal to digital one, ) Reduce noise ,6) Increase range xxi) In digital logic, a counter is a device which ‘2) Counts the number of outputs bY'Stores the number of times & particular event or process has occurred c) Stores the number of times a clock pulse rises and falls d) Counts the number of inputs soi) The output of sequential cieuit depends on (a) Present input only, (b) Past output only, (f) both Present input ‘and Past output (4) Past input only. xxiii) When the set is enabled in S-R (@) Indeterminate flop, then the output will be (a) set, (b) Reset,(c) No change xxiv) 32:1 MUX required. number of select lines. 2) 2,0)3,94,4)5 xxv) Shifting binary data tothe left by one bit position using shift registers amounts to--— 8) division by 2, b) subtraction of 2c) adition of 2, multiplication by 2. GreUuP-B 2 3 Pa ae ‘between Zener breakdown and avalanche breakdown and discuss V-I characteristics of Zener Diode & explain how it can be used as a voltage stabilizer 243438 3. ®) Compare between CB,CE, i my ,CE,CC transistor configurations. b) Why CE ion is Wo) Dae ln een Apnand Be) NY Econ ont aes 4 ow i ‘rite short notes on (i) Colpitts Oscillator (ii) Wien. Bridge Oscillator 4+4=8 © scanned with OKEN Scanner4) What is the equivalent circuit of UIT? b) Show UIT as relaxation Oscillator. 345-8 Write short notes on: (i) Ring counter, (i) Synchronous counter 444-8 «) Design Full-Adder b) Design a 1x4 Demmultiplexe, 444-8 8) Write down the operating principle of R-2R Ladder D/A using suitable diagrams | +) Explain the operation of Dual slope type A/D converter using proper diagrams. What is race around condition? How you can avoid itby J-K Master Slave Flip Flop? Beir, © scanned with OKEN Scanner