Addition of capacitor creates a phase shift of 90 degrees between the two windings which make it selfstarting. Objective single phase induction motors questions and. Speed control in three phase induction motor mcqs with answers. Sep 16, 2018 this video contains very important mcq of induction motor this video is important for those who is preparing for competitive exam related to elctrical engg. The rotor will constantly be turning to align its magnetic field with that of the stator field. Uppcl je previous years question paper download pdf. Multiple choice questions on three phase induction motor electric. Single phase induction motor multiple choice questions mcq. Introduction types of electrical machines types of 3ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. 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. State performance of a capacitorstart singlephase induction. Three phase induction motor mcq questions answers electrical engineering.
Speed control in three phase induction motor mcqs with answers q1. Latest automobile engineering multiple choice questions and answers pdf free download. Single phase induction motors mcqs answers pdf electrical. Polyphase induction motor mcq with explanation in case of 3 phase induction motors the ratio of core length to pole pitch for minimum cost is. Three phase induction motor electrical engineering mcq questions answers. Consider a normal slip ring induction motor having three phase winding on the rotor as shown in the fig. They are found everywhere from a small workshop to a large manufacturing industry.
This document is highly rated by electrical engineering ee students and has been viewed 2456 times. Equivalent circuit of three phase and single phase induction motor. Polyphase induction motors objective type questions and. The most common type of ac motor being used throughout the work today is the induction motor. Apr 11, 2020 ssc je electrical important mcq pdf part 3 note download link of pdf given at end of post 1. Thus from the working principle of three phase induction motor, it may be observed that the rotor speed should not reach the synchronous speed produced by the stator. Single phase induction motors multiple choice questions. Polyphase induction motor mcq set 03 objectivebooks. Nov 27, 2019 thus from the working principle of three phase induction motor, it may be observed that the rotor speed should not reach the synchronous speed produced by the stator. Nov 04, 2012 introductionan induction motor im is a type ofasynchronous acmotor where power is supplied to therotating device bymeans ofelectromagneticinduction three phase induction motors 4. In a threephase induction motor, the number of poles in the rotor winding is always a zero b more than the number of poles in stator.
Ppt threephase induction motor electrical engineering ee. If one of the parallel resistors in any parallel circuit is removed from the circuit, then the total resistance a doubled b increases c remains the same d decreases answer. If the speeds become equal, there would be no such relative speed, so no emf induced in the rotor, and no current would be flowing, and therefore no torque would be generated. Three phase induction motor working principle in tamil. Starting method for induction motors a 3phase induction motor is theoretically self starting.
Ppt threephase induction motor electrical engineering. Pdf chapter 4 electrical machines gate previous year. Automobile engineering important multiple choice questions with answers pdf file fr. If one of the lines is open, the motor becomes singlephase, and no singlephase synchronous motor, as such, is selfstarting. In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. Alternator multiple choice questions mcq and answers. This will link and cut the rotor conductors which in turn will induce a current in the rotor conductors and.
The synchronous induction motor provides constant speed, large starting torque, low starting current and power factor correction. Candidates must appear in a computer based online test or cbt or written test for the upcoming junior engineer trainee je t posts in uppcl upptcl. Multiple choice questions on three phase induction motor scribd. Three phase induction motors mcqs with explanatory answers. In a three phase induction motor, the number of poles in the. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. A successful salesman for general electrics motor division once remarked to one of your instructors that, when asked by a customer how a motor. Here we will see a detailed article related to the starting methods of threephase induction motor. If the frequency of 3 phase supply to the stator of 3 phase induction motor is increased, then. Multiple choice questions on three phase induction motor. Construction of three phase induction motor electrical4u. We also discuss the construction of a three phase motor including its. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. The three phase induction motor is the most widely used electrical motor.
Sep 02, 2014 110 top single phase induction motors electrical engineering multiple choice questions and answers latest single phase induction motors questions and answers list 1. They have very simple and rugged almost unbreakable construction. The method which can be used for the speed control of induction motor from stator side is. The basic idea of an electric motor is to generate two magnetic fields. When the rotor of 3 phase induction motor run at synchronous speed, its rotor frequency will become a.
Dc generator click here to download dc motor click here to download single phase induction motor click here to download pdf of 1phase i. Losses and efficiency of three phase induction motor. Induction motor might be worked as either motors or generator. Difficulty in starting may also be caused by an open circuit in one of the lines to the motor. For explanatory answer, click on the toggle button labeled as check explanatory answer.
Apr 07, 2020 ppt threephase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. 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. Ssc je electrical important mcq pdf part 3 note download link of pdf given at end of post 1. I like teaching, keen to learn new things and methods. It is simple and rugged in construction it is relatively cheap induction motors. Three phase ac circuits mcqs with explanatory answers 1. Explain starting methods of 3 phase induction motor. In threephase induction motors sometimes copper bars are placed deep in the rotor to a improve starting torque b reduce copper losses c improve efficiency d improve power factor ans. If the frequency of 3phase supply to the stator of 3phase induction motor is increased, then. Sep 02, 2014 101 top polyphase induction motors electrical engineering multiple choice questions and answers. Home category electrical engineering mcq questions and answers 3 phase induction motors 1 the frequency of the induced emf in an induction motor is a. Most important mcq or objective questions on induction motor are discussed in this page. If the frequency of 3phase supply to the stator of 3. Three phase induction motor or ac motor is started by itself but we require some starter or other methods for proper starting and controlling induction motor.
Multiple choice question mcq of induction motors page1. Single phase induction motor split phase start or induction run motor d reluctance motor e synchronous motor. As compared to dol starting a cage induction motor with star delta starting shall have a. M motor mcq three phase induction motor click here to download pdf of 3phase i. The autostarters using three auto transformers can be used to start cage induction motor of the following type star connected only delta connected only a and b both none of the above 1. Multiple choice questions on three phase induction motor free download as word doc.
Historythe induction motor with a wrapped rotor wasinvented by nikola tesla in 1888 in the unitedstates. The step angle of this step motor is a 3c b 6c c 9c d 18c mcq 4. Electrical machine mcq pdf october 18, 2019january 20, 2020 electricalworld dc generator click here to download dc motor click here to download single phase induction motor click here to download pdf of 1phase i. In a three phase induction motor the resultant flux is constant and is a. Compared to the shaded pole motor, these motors provide much greater starting torque. The 3 phase set of currents, each of equal magnitude and with a phase. Jul 18, 2017 3phase induction motor working principle of operation in tamil with demonstration. A threephase induction motor consists of two parts stator the stationary part and rotor. 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. In a threephase induction motor a power factor at starting is high as compared to that while running. The stator of an induction motor consists of 3phase windings, which when connected to a 3phase supply creates a rotating magnetic field.
For reason of economy, most houses, offices and also rural areas are supplied with single phase a. Three phase induction motors part 1 here are some practice mcq related to three phase induction motors. Induction motor b threephase series motor c schrage motor d hysteresis motor ans. Induction motor basics, single phase and three phase. In a three phase induction motor a power factor at starting is high as compared to that while running. What are the advantages and disadvantages of induction motors. A 3 phase induction motor can be used for different applications with various speed and load requirements. Polyphase induction motors, 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. Speed control in three phase induction motor mcqs with. At zero in an induction motor a motor runs as a generator b motor does not run c the motor runs an at synchronous speed d slip produced is zero. The speed of a 3 phase induction motor is controlled from.
Synchronous induction motor electrical engineering. Three phase induction motor mcq questions answers electrical. Power transmission, distribution and sub stations public. Hindi three phase and single phase induction motors. A three phase induction motor runs on a three phase ac supply. The starting torque of a three phase induction motor can be increased by a increasing slip b increasing current. Dec 29, 2017 apr 07, 2020 ppt three phase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. Speed control in three phase induction motor mcqs with ans. Dec 21, 2018 the capacitor is used in single phase induction motor for creating a phase shift.
This course is about a brief explanation of single phase and three phase induction motors with their. Almost 80% of the mechanical power used by industries is provided by three phase induction motors because of its simple and rugged construction, low cost, good operating characteristics, the absence of commutator and good speed regulation. Three phase induction motors mcqs with explanatory answers 1. Induction motor has the same physical stator as a synchronous machine with an alternate rotor development. Here we will see a detailed article related to the starting methods of three phase induction motor. Strength of materials objective questions with answers set 10. In electrical equipment the anchors winding would be induced by the magnetic field, although the rotor takes this part in threephase induction motors. A three point starter is considered suitable for a shunt motors b shunt as well as compound motors. Different types of single phase induction motor mcqs with answers.
Three phase induction motor working principle in tamil youtube. The capacitor is used in single phase induction motor for creating a phase shift. Be careful it can hurt to tangle with a three phase motor. A simple explanation of how a 3 phase induction motor works. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. Polyphase induction motor mcq with explanation in case of 3 phase induction motors the ratio of core length to pole pitch for minimum cost is taken as. Three phase ac circuits mcqs with explanatory answers three phase ac circuits mcqs with explanation. Be careful it can hurt to tangle with a threephase motor. In a threephase induction motor, the number of poles in the rotor winding is always.
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