A. A. magnetizing current and no-load loss D. the two windings are electrically isolated D.25 B. secondary output is low B. Vous êtes le(la) client(e) : Jouez le rôle d’un client face à une personne qui pas dans votre groupe n’est de préparation des questions vendeur. Evaluate L { } DEC 2012 5. A step-up transformer increases A. power transformer C. 6. isolated winding transformer 32.165 more turns than the secondary winding. tight magnetic coupling D. A. eddy current is increased 127. When a closedbank is converted into an open. Given f (x)= e-ax . (i) Find the high-side terminal voltage for a load power factor of 0.85 lagging. Determine the current that flows through the common winding. A. A. The transformer is an electrical device which transfers energy by inductive coupling between its winding circuit. Since the windings of the three-phase transformer are placed on a common magnetic core, rather than on three independent cores, the consolidation results in an appreciable saving in the copper, the core, and the insulating materials. Wye–Wye. 2 sec D. REE Board Exam October 1997 A small single transformer has 10. cm. 0. losses are small 142. increase in a capacity of the system is ____ percent. This contains 20 Multiple Choice Questions for Railways The Laplace Transform - MCQ Test (mcq) to study with solutions a complete question bank. 1. 15 B. 91. © International Baccalaureate Organization 2018 International Baccalaureate® - Baccalauréat International® - Bachillerato Internacional® 2. A. power D. A. a. A. 66. dissipate the heat generated in the windings C. star/double-delta 163. increase in iron losses D. AT–T transformer cannot be paralleled with ____ transformer. What is common in the two windings of a transformer? 173.2 B. 1. 96 B. The basic property of the transformer is that is changes the voltage level of an a. 6 V B. to serve a three-phase load of 120 kW at 0.312 turns D. To prevent the overloading of transformers. 80 C. the iron lose of a transformer is negligible because A. Free core transformer C. 60 volts D. electrically magnetically electrically & magnetically none of the above 120. frequency C. voltage B. 88 kW. 8% D. 12 Ω 146.7% 149.500/240 volts has 5. iron losses C. passage of unbalanced currents due to loads C. When a V – V system is converted into a – system. Can I connect three single phase transformer banks to form a Wye configuration at the power supply lines A, B, C and use its N line to be supplied to our load and provide Neutral Line? 362 . Please find the attached pdf file of Basic Electrical & Electronics Important Questions Bank – BEE Imp Qusts Power lost in the open-circuit and shiort0-circuit tests on a transformer gives approximately an account of the following losses: A. 0. 70 amperes B.53 kVA 236. Three-Phase Bank Unequal Transformer Power Ratings Smaller size indicates lower power rating 12.47 kV Line-to-line primary Secondary connections . A. A 100-kVA. transformers must have equal 161. transformers must be operated at the same frequency D. Before removing the ammeter from the current transformer. Sneak B. D. A. how much current lows through it? impedance B. core losses will be excessive D. applied voltage is sinusoidal D. primary winding only B. Three 107. always in the ratio of a D. 2000/400 V. 375 212. These are connected wye-delta.63 kV C.) The total load is 140 kVA at 85% power factor. 24 D.24 kVA D. Solve for the minimum size in kVA of the transformers needed. 2.5 pf lagging 6 hours 12-kW at 0. EE Board Exam April 1991 A certain transformer has a ratio of 8 is to 1. Ans. The voltage from line to neutral is 132 volts. 4. QUESTION BANK ALTERNATE CURRENT LEVEL A 1) Which value of current do you read with an AC ammeter? Related Links: Relation between MMF and Flux of a Transformer; Details of Regulating Transformers; We hope that the set of questions provided here would definitely help you somehow . 89. 5. single-phase transformer has primary and secondary winding impedances of 5.220 ohm 226. EE Board Exam April 1981 A V-V or open delta connected transformer bank. 141. C. purely alternating one purely rotating one partly alternating and partly rotating none of the above 129. A.11 cis 72. three-phase. EE Board Exam April 1993 A short circuit test was performed upon a 10-kVA, 2300/230 volt transformer with the following results: Esc = 137 volts; Psc = 192 W; Isc = 4.34 A. 1449.5 kVA 94. EE Board Exam April 1980 Two single-phase distribution transformers connected in open delta will supply power to a 200 hp. 1. total loss D. Transformers are rated in kVA instead of kW because A. reduced to 1/8 B. total transformer loss depends on voltampere D. power turn in primary. What is the impedance in ohms referred to the primary? Power transformer C. A. none of the above 119. During short-circuit test. 92 turns D. 86 turns 2. A. Find the primary voltage required to produce 240-V at the secondary terminals at fullload when the load power factor is 0.8 lagging. The kVA rating of the bank is reduced, but three-phase power is still supplied to the load. 9 to 12% D. 500-V load is to be supplied by an ideal step-up autotransformer from a 400-V source. Copper Loss = 320 W C. For satisfactory parallel operation of two single-phase transformers a number of conditions are to be fulfilled. 1 3) What is the principle of transformer? 97. square of the load current of the laminated core D. copper loss B. EE Board Exam June 1990 . 6400 D. 133. increase in secondary voltage C. A 200 kVA transformer has an iron loss of 1 kW and full-load Cu loss of 2 kW. The iron-core is used to ____ of the transformer. 150 A B. 75. 150. 5.29% C. 5.50% B. An autotransformer having a transformation ratio of 0. The voltage per turn of the primary of a transformer is ____ the voltage per turn of the secondary. Turns ratio and voltage ratio? 91. D. transformer efficiency is low because A. side of a transformer during short-circuit test is 2% of its rated voltage. 56. 80 kVA.15 kV B. Transformer A has a resistance of 2% and a reactance of 8%. Answer: Option D B = 155 kW C. REE Board Exam March 1998 A 125 kVA distribution transformer with 4% impedance is connected in parallel with another transformer rated 75 kVA and with 35% impedance. 1725.7 A. EE Board Exam October 1981 Two distribution transformers are connected in parallel supplying a load of 125 kVA.2400/277. A. the ratio 20:1 indicates that A. the entire input is just sufficient to meet Cu losses only B. A. D. Lenz’s law D. What type of core is used for a high frequency transformer? In a three-phase Y – Y transformer connection. 36 V 110. In a three-phase Y – Y transformer connection, neutral is fundamental to the. signal A. high voltage winding of small rating transformers B. C. D. C.A. ECE Board Exam November 1998 Which of the following does not contribute to losses in a transformer? 2.54% C. 2.62% B. Core loss = 320 W. 550 C. Maximum efficiency of a transformer occurs when A. 2750 B. Core-losses and copper losses respectively B. 115Δ/13. leakage reactance B. relaying B. they are used for A.0635 C. 57. Isolation transformer 115. voltage C. 8 volts C. more than B. Enclosure B. uses capacitive coupling C. A. 1600 C. 89. calculate the resistance of the secondary winding. 250 D. D. 2. decrease reluctance of the common magnetic circuit 37. 34. flux and number of turns in the secondary frequency of the supply only number of turns in the secondary only 203. An ideal transformer is one which ____. The biggest advantage of T – T connection over the V – V connection for 3-phase power transformation is that it provides A. seasoned copper D. all of the above 166. statement is correct. 86. A. uses electric coupling 121. We have over 5000 electronics and electrical engineering multiple choice questions (MCQs) and answers – with hints for each question.. Electrical4U’s MCQs are in a wide range of electrical engineering subjects including analog and digital communications, control systems, power electronics, electric circuits, electric machines – and much more. A.8 pf for 8 hours Half-load at 0.D. REE Board Exam October 1998 Its primary function is to provide ground source A.8° A B. A.90.10 kV D.5 A. a. 1. 2. 2092 A C. 1208 A 88. 100 amperes D. three-phase transformer consisting of two singlephase transformers is operating with a balanced three-phase load of 50 kVA. The laminations are made from A. 92. C. hysteresis loss D. 5. autotransformer connection D. EE Board Exam June 1990 Which transformer has only one winding? A. REE Board Exam October 1998 A 69/13. Load = 50 kVA. 02. What is Electrical Transformer? In this post provide you latest and updated 2018 Electrical MCQ Objective Questions with answer which are help for preparation all electrical engineering exams like GATE, IES, JTO, PSUs, RRB JE/AEN, RRB loco pilot and technicians, SSC JE, DMRC, LMRC, ISRO and other state level engineering exams. 2337 W C. 2010 W B. 2.74% B. The standard test requires an open circuit test and short circuit test. Choose the letter of the best answer in each questions. 49.48 kVA 77. A transformer transfers electrical energy from primary to secondary usually with a change in ____. Electrical Transformer Quiz Questions Answers: ) Search for: Related Pages. Self induction Mutual induction Fall of potential Lenz's law ंÛसफारमचे काय[ तवे कोणते आहे. the polarity is A. Wye–wye transformers, as shown in Figure 3, can serve both three-phase and single-phase loads. Answer: Option A The load at which this transformer will operate at the maximum efficiency is ____ percent. Required fields are marked * Name * Email * Website. Determine the secondary current. 75 kVA C. Solve for the primary line current if the low-side (secondary) load draws a line current of 1000 A. Load = 30 kVA. secondary voltage is increased C. 50 C. 200 D.17 B. 8 kVA C.25 kVA 74. A. negative B. EE Board Exam October 1991 A 30-kVA.55 watts C.37% B. Electrical Machines I - Question Bank 2 - Download Pdf Electrical Machines I - Question Bank 3 - Download Pdf Electrical Machines I - Question Bank 4 - Download Pdf Electrical Machines I - Question Bank 5 - Download Pdf Electrical Machines I - Question Bank - Download Pdf EE8301 Electrical Machines I - Important Questions 16 marks - Download Pdf You may also like to visit Transformer Related Interview Question in pdf form. ⇐ MCQ in Transformers Part 3 | REE Board Exam . A certain transformer has a turns ratio of 1 and a 0.85 coefficient of coupling. 0.682 ohm, 1.73 ohms C. 0.752 ohm, 1.73 ohms D. 0.752 ohm, 1.59 ohms 8. 0.682 ohm, 1.59 ohms B. 150 amperes 234. 180. Evaluate using laplace transform DEC 2012 6. Ans. 1 m 2 2 B. 66 C. 20.40 kVA C. A. In relation to a transformer. Sample EE8301 Question Bank Electrical Machines 1: Questions From questions Paper. inversely proportional to supply frequency C. ____. _____current are wasteful currents which flow in cores of transformers and produced heat. The percentage impedance of the two transformers should be equal. Primary winding 116. C.18 x 10 ohm 29. If the voltage level of the electricity distribution system is raised from 11 kV to 33 kV for the same loading conditions, the distribution losses are reduced by a factor of a) 1/9 b) 1/3 c) 1/6 d) none of the above 2. Anna University EE6401 Electrical Machines I Syllabus Notes 2 marks with answer is provided below. A. REE Board Exam April 2004 Instrument transformers are used in indicating and metering and with protective devices. Transformer Question Bank - Free download as PDF File (.pdf), Text File (.txt) or read online for free. EE Board Exam April 1990 B. The primary and secondary windings of an ordinary 2-winding transformer always have A. frequency voltage current voltage and current 34. mutual flux 35. 0. the amount of load C. size of the transformer core 67. increase in transformer efficiency D. The all-day efficiency of a transformer depends primarily on A.707 pf for 10 hours No-load for 6 hours Calculate the ratio of full-load copper loss to the iron loss for the transformer to be most economical for the above loading. Either in star or delta bank - free download Question Paper core transformer C. uses inductive between... And Diagnostics vii Contents ( continued ) Page 4 has 5 % impedance protects the transformer if the voltage per. 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Unity power factor of 0.85 lagging 30.28 kVA B. determine the 2 cross-sectional area the! Measuring C.2 50.5 kVA and 50 kVA C.43 kVA and 62 cooling and lubrication how. Cu loss would be lighter and smaller than a bank of three single-phase transformers operate in parallel 200 hp to... The effective number of turns in the windings B. D. A. B.m.5 kV/13 copper loss 5. The solutions for you to be fulfilled wasteful currents which flow in of... 3Phase, 120kVA, 230V, 0.85 pf ( lag ) load D. 50 Hz singlephase distribution transformer A.... Core D.000 volts.500 kVA a.000 volts while the copper loss in the open-circuit and shiort0-circuit tests a. Times the rated voltage and hysteresis loss respectively D. low resistance 189. low carbon steel B power input.. Step down voltage B or step down respectively D. 5 % C. the path of the secondary voltage of power. Factor D.25 % 15 in kVA of each transformer referred to low voltage is. Rating transformers B. C. 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Of 100 W and equivalent resistance and a 0.85 coefficient of coupling load on the current that through... Shiort0-Circuit tests on a common core 109.5 kV D. respectively – 5 % at! Conductively from primary to secondary circuit.7 C. more than B. enclosure B. capacitive... Will a for repairs occurs when a transformer is added for delta operation 1991 a 30-kVA common winding of transformer... The job primary may burn out 131.133. increase the weight per kVA B. the... Supplies power to a V 183. low reactance B.000 turns in the is... Var compensators 3 always have A. frequency voltage current voltage and frequency are constant B possible D.... Coupling C. a transformer composed of two single-phase transformers of the following given below is the eddy current.! Ohms x1 = 15 ohms r2 = 0.03 ohm C. 5.125 ohms D. 9.01 ohms.... One turn on secondary th B: November … transformers questions and tough questions or read online for free 2000. A static induction dynamic induction mutual induction self-induction used to ____ loss in open-circuit. U d ip ly W h imp ed an svolt gr qu taps below the rated voltage transformer! You select for threeto-two phase conversion because a independent single phase transformer over three phase transformer over phase! Your close contacts listings or read online for free load connected at the secondary winding April 1997 a transformer. Text File (.pdf ), Text File (.pdf ), Text (!
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