In this core type transformer, the windings surround a considerable part of the core. Threephase transformers a transformer bank composed of three singlephase units may be replaced by one 3phase transformer the magnetic core has three fluxcarrying legs two yokes, bottom and top, couple the flux of the three legs the sum of the three fluxes equals zero each leg contains the primary and secondary windings. Mar 30, 2020 ppt single phase transformer electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Three phase connection of single phase transformers introduction the primary and secondary windings of three single phase transformers can be connected in di erent con gurations to meet speci c 3 phase system requirements. The maximum value of the magnetic flux density is 1. This document is highly rated by electrical engineering ee students and has been viewed 6598 times. Three phase ac circuits mcqs with explanatory answers three phase ac circuits mcqs with explanation. For the parallel operation of single phase transformers it is necessary that they should have a same efficiency. For ideal transformer efficiency is 100% both for ideal transformer voltage regulation is 100% none of these answera scott connections are used for single phase to three phase transformation three phase to two phase transformation any of the above. Download important questions of transformer with solution. Electrical transformer important 30 objective questions. Single phase transformers accept single phase ac power and output single phase ac power, typically at a higher or lower voltage level. Efficiency in single phase transformer mcqs with answers. Wyewye and deltadelta transformers do not cause any phase shift from primary to secondary.
The three phase system application means using three single phase units connected in the three phase system. The noload current drawn by the transformer is usually what percent of the fullload current. Harikesh yadav general, online mcq ee november 6, 2016. A single phase, 2,200200 v transformer takes 1 a at the ht side or no. Square d brand ex low voltage distribution transformers. Losses working and construction of transformer mcq. To understand the basic working principle of a transformer. Equivalent circuit diagram of single phase transformer. Introduction to single phase transformers electrical.
This is a more expensive solution, and it is used in the high voltage power system. A single phase transformer has its maximum efficiency at 60 percent of full load. Transformers mcqs with explanatory answers electrical technology. An addition of inductor for high hp motor wont make the motor as selfstarting even if it starts it will rotate at very less speed and inherently. The primary and secondary windings of an two winding transformer always have. In a split phase motor, the running winding should have a high resistance and low inductance.
Bil basic impulse level is a means to express the ability of the insulation system to withstand high voltage surges. Single phase induction motors multiple choice questions and answers pdf free download,interview questions,objective type questions,lab viva manual. How to calculate the required capacity kva rating or. Latest automobile engineering multiple choice questions and answers pdf free download. In a split phase motor, the running winding should have a high resistance and low inductance single phase induction motors multiple choice questions and answers pdf free download,interview questions,objective type questions,lab viva manual. Buck boost transformer twowinding, single phase transformer with low voltage secondary windings which can be connected as an autotransformer.
Most asked objective questions or mcq on single phase motors. The single phase is used in a place where less power is required and for running the small loads. Deltawye transformers have a 30degree phase shift which is discussed below. For the parallel operation of single phase transformers it is necessary that they should have a same efficiency b same. Apr 12, 2019 hello everyone, this new technical session discusses the single phase transformer mcqs and its concepts which is important for rrb je 2019 mains and mpsc 2019 prelims. Theory of operation of singlephase transformers custom. Polarity test of a singlephase transformer electrical. Three phase ac circuits mcqs with explanatory answers. The major usage of transformer is to either to vary relative voltage of the circuit or isolate it. Equivalent circuit diagram of a transformer is basically a diagram which can be resolved into an equivalent circuit in which the resistance and leakage reactance. For explanatory answer, click on the toggle button labeled as check explanatory answer. The shell type transformer is a simple rectangular form and the core surrounds the considerable portion of the windings.
The essential condition for parallel operation of two 1 phase transformer is that they. Hello everyone, this new technical session discusses the single phase transformer mcqs and its concepts which is important for rrb je 2019 mains and mpsc 2019 prelims. Transformer is an electrical device that makes the transfer of energy by forming inductive coupling between the winding of its circuits. Transformers multiple choice questions and answers mcq. Determine the primary and secondary fullload currents of the trans. A single phase transformer has 480 turns on the primary winding and 90 turns on the secondary winding. Download important questions of transformer with solution in. An electrical power transformer is a static device, which transforms electrical energy from one circuit to another without any direct electrical connection. A capacitorstart single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. Arc horn are used in high voltage transmission line why. Dec 18, 2017 apr 08, 2020 introduction to single phase transformers electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. A transformer is an telectrical apparatus designed to convert alternating current from one voltage to another. Energy is transferred from one circuit to one or more circuits via electromagnetic induction. Here in this post we have tried to made available important questions of transformer explaining its working principle, its types, applications and uses in detail in order to explain related doubts.
Ppt single phase transformer electrical engineering ee. While conducting the sumpners test, the primaries of the two identical transformers are. Single phase induction motors mcqs for preparation of fpsc, nts, kppsc, ppsc, and other test. It also performs this with the help of mutual induction between two windings.
Top 30 mcqs on single phase transformer mpsc 2019 rrb je 2019 with. The secondary winding of which of the following transformers. Single phase transformer electrical engineering mcq. In a transformer, primary and secondary windings have some resistance. Three phase transformers electrical machines questions and. Otherwise, with incorrect polarity, it is not possible to connect them in parallel. Transformers, electrical engineering multiple choice questions objective type questions, mcqs, with question and answers, download free pdf, electrical engineering, multiple choice questions, objective type questions, electrical engineering short notes, rapid fire notes, best theory. Top 30 mcqs on single phase transformer mpsc 2019 rrb je. Sistece 2 coil 1 i1t i2t coil 2 m e1t e2t s1 s2 i1t i2t the transformer primary has n1 turns secondary has n2 turns v2 3. A singlephase transformer with a 2kva rating has a.
Addition of capacitor creates a phase shift of 90 degrees between the two windings which make it selfstarting. Top most asked objective questions or mcq on transformer for electrical engineering electricalnotes4u. Multiple choice questions mcq on single phase motors for electrical engineering. Efficiency ratings of low voltage drytype distribution transformers single phase1 1 single phase ventilated transformer efficiencies remain the same as the 2007 levels. Dec 29, 2017 mar 30, 2020 ppt single phase transformer electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Equivalent circuit diagram of a transformer is basically a diagram which can be resolved into an equivalent circuit in which the resistance and leakage reactance of the transformer are imagined to be external to the winding. A 25 kva single phase transformer has the p rimary and secondary number of turns of 200 and 400, respectively the transformer is connected to a 220v, 50hz source. Top most asked objective questions or mcq on transformer. Single phase induction motor multiple choice questions mcq. M motor mcq three phase induction motor click here to download pdf of 3phase i. Single phase induction motors multiple choice questions.
Generally, the core of the coretype transformer is a rectangular shape and the coils are both circular or rectangular in form and the windings are located on the opposite limbs of the core. There are four different ways in which single phase transformers can be connected to form three phase banks. For a transformer, no load primary current i0 has two components, magnetizing. Let, r 1 is the resistance of the primary winding and r 2 is the resistance the secondary winding which is shown in the figure. Single phase overhead distribution transformers power partners, inc. The torque developed by an induction motor is proportional to the slip.
Electrical transformer important 30 objective questions and answers in hindi in this video we will know 30 important objectives types questions and answers of electrical transformer. In this post, we are going to share multiple choice questions mcq on transformer for electrical engineering students. Single phase transformers retain their design, ee prefix, and catalog numbering structure. Three phase connection of singlephase transformers introduction. Polarity test of a single phase transformer polarity testing of transformers is vital before connecting them in parallel. A single phase transformer is a type of power transformer that utilizes. Ermco single phase pad mounted distribution transformers are designed and manufactured in compliance with all applicable ansi and rus standards. Transformer basics electric machines single phase transformer three phase transformer transformer type instrument transformer transformer test transformer accessories transformer oil maintenance of transformers installation of transformers transformer protection. Single phase transformer electrical engineering mcq questions and answers.
Single phase transformers selection guide engineering360. How to calculate the required capacity kva rating or amperage capacity for single and three phase transformers. Apr, 2019 transformer basics electric machines single phase transformer three phase transformer transformer type instrument transformer transformer test transformer accessories. Three phase connection of singlephase transformers introduction the primary and secondary windings of three single phase transformers can be connected in di erent con gurations to meet speci c 3 phase system requirements. It is necessary that the proper impedance be used to represent the primary system. Jan 02, 2019 the three phase system application means using three single phase units connected in the three phase system. Rating of a single phase transformer in kva kva v x i now p v x i primary voltages x primary current p 1v x 4. Transformers which of the following statements regarding an idel single phase transformer having a turn ratio of 1.
Section d ry tp ei sbu ona f m 1 transformer questions. C rise, and designed for usual service conditions per ansi c57. The main principle of operation of a transformer is mutual inductance between two circuits which is linked by a common magnetic flux. Sumpners test in singlephase transformer mcqs with answers. Most asked objective questions or mcq on transformer. Three phase connection of singlephase transformers. Slip, s, is defined as the difference between synchronous speed and operating speed, at the same frequency, expressed in rpm, or in percentage or ratio of synchronous speed. Sue the varying current flowing through the primary winding creates a magnetic flux inside the core of the transformer and in secondary winding. Professionals, teachers, students and kids trivia quizzes to test your knowledge on the subject. At synchronous speed, the slip is zero and hence torque developed by the.
Sumpners test in single phase transformer mcqs with answers q1. Single phase transformer electrical engineering mcq questions and answers home category electrical engineering mcq questions and answers single phase transformer 1 if r 1 is the primary winding resistance and r 2 is the secondary winding resistance then the equivalent resistance of the transformer as referred to the primary is. Home category electrical engineering mcq questions and answers single phase transformer. Transformers multiple choice questions and answers mcqs electrical engineering interview transformers viva lab manual pdf free download.
Transformer multiple choice questions mcq and answers. The advantages of three single phase units are transportation, maintenance, and spare unit availability. Home transformer multiple choice questions and answers pdf. Oct 18, 2019 dc generator click here to download dc motor click here to download single phase induction motor click here to download pdf of 1phase i. Every mcq set focuses on a specific topic in transformers subject. Click to share on facebook opens in new window click to share on telegram opens in new window click to share on whatsapp opens in new window. Mcq quiz on transformers multiple choice questions and answers on transformers mcq questions quiz on transformers objectives questions with answer test pdf. Single phase induction motors mcqs for preparation pakmcqs. They are also suitable for light commercial loads, industrial lighting and diversified power applications. Nov 12, 2019 basic electrical engineering mcqs pdf click here to download pdf of basic electrical mcq ac fundamental mcqs pdf click here to download pdf of ac fundamental mcq single phase ac mcqs pdf click here to download three phase ac mcqs read more. Calculation of kva capacity for a single or three phase transformer, based on winding voltage and amperage information. Dec 21, 2018 the capacitor is used in single phase induction motor for creating a phase shift.
Equivalent circuit in singlephase transformer mcqs with answers. This document is highly rated by electrical engineering ee students and has been viewed 1869 times. Two or more single phase transformers connected together to supply a three phase load. Short circuit and open circuit test in single phase transformer. Transformer basicsworking principle,construction,types. In this page you can learn various important single phase induction motor multiple choice questions answers,single phase induction motor mcq,sloved single phase induction motor objective questions answers, single phase induction motor mcq pdf etc. In a single phase series motor the main purpose of inductivelywound compensating winding is to reduce the a reactance emf of commutation b rotational emf of commutation. Single phase ac circuits mcqs with explanatory answers. Single phase transformer and applications of single phase. A basic transformer consists of two coils that are electrically separate and inductive, but are magnetically linked through a path of reluctance.
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