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. Three phase ac circuits mcqs with explanatory answers. Threephase ac induction motors are optimal for unidirectional and continuous operation such as a conveyor system. The difference in speed between rotor, the synchronous speed and the rotating. The induction motor is started by itself that we know. The complete circuit diagram of a 3 phase induction motor can be drawn with the help of.
What is common to all the members of this family is that the basic physical process involved in their operation is the conversion of electromagnetic energy. Home category electrical engineering mcq questions and answers 3 phase induction motors. Machine, 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. Apr 17, 2019 mcq on single phase induction motor pdf mcq on induction motor electrical 3 phase induction motor mcq pdf induction motor question bank rotor of three phase induction motor. An induction motor also known as an asynchronous motor is a commonly used ac electric motor. Jan 02, 2020 so when 3 phase ac supply is given to the stator windings of the induction motor, rmf revolving magnetic field is produced, that links with the conductor of cage rotor and produces emf, so a current start flowing through the conductors, hence torque is developed which causes the rotor to rotate.
Kirloskar indus3 series three phase induction motors are specially designed in accordance with. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Jul 18, 2017 3phase induction motor working principle of operation in tamil with demonstration. Three phase induction motor introduction basic electrical.
The threephase induction motor is the extensively used for various kinds of industrial drives. In this method of speed control of three phase induction motor, the two three phase induction motors are connected on a common shaft and hence called cascaded motor. One single phase wattmeter plus miscellaneous apparatus as needed. Jan 02, 2020 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. When the 3 phase stator windings are fed by 3 phase supply, a magnetic flux of constant magnitude which is rotating at synchronous speed is set up. Three phase ac circuits mcqs with explanatory answers 1. Sep 02, 2014 101 top polyphase induction motors electrical engineering multiple choice questions and answers. Three phase induction motor working principle in tamil youtube. This classification of induction motor is based on the type of power supply required for its operation. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. An electrical motor is a device that has brought about one of the biggest advancements in the fields of engineering and technology ever since the invention.
The most common type of ac motor being used throughout the work today is the induction motor. Induction motor 1 chapter 3 induction motor bee23 electrical machine power system 2 learning outcomes. It is based on freescales 56f800e microcontrollers. Rotating magnetic field an overview sciencedirect topics. Sep 02, 2014 110 top single phase induction motors electrical engineering multiple choice questions and answers. Applications of three phase induction motors of size varying from half a kilowatt to thousands of kilowatts are numerous. Induction motor basics, single phase and three phase. 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. The stator of three phase induction motor is made up of numbers of slots to construct a 3 phase winding circuit which we connect with 3 phase ac source. 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 1 phase i.
Speed control in three phase induction motor mcqs with. The stator of an induction motor consists of 3 phase windings, which when connected to a 3 phase supply creates a rotating magnetic field. Presented here is a robust system for switching onoff, varying the speed and direction of rotation of an industrial 3 phase induction motor using vfd and plc. Three phase induction motors mcqs with explanatory answers. M motor mcq three phase induction motor click here to download pdf of 3 phase i.
The major difference between them is that transformer is static in nature i. Aug 21, 2015 3 phase induction motors related mcq objective questions with answers 1 which of the following statements about a three phase squirrelcage induction motor are false. A 3 phase induction motor can be used for different applications with various speed and load requirements. Various applications toshiba motor is used for various applications. Three phase induction motors mcqs with explanatory answers 1. The 3 phase set of currents, each of equal magnitude and with a phase. Frame size 180m and above, 380660v50hz is standard. Advantages of 3 phase induction motor generally easy to build and cheaper than corresponding dc or synchronous motors induction motor is robust. Latest automobile engineering multiple choice questions and answers pdf. Three phase ac induction motors are widely used in industrial and commercial applications. A three phase induction motor runs on a three phase ac supply. A 3 phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field.
Single phase induction motors mcqs answers pdf electrical. A 4 pole, 3 phase double layer winding is housed in 36 slot stator for an ac machine with 60 phase spread. The basic idea of an electric motor is to generate two magnetic fields. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. These motors are selfstarting and use no capacitor, start winding, centrifugal switch or other starting device. Dc motors depend either on mechanical or electronic commutation to create rotating magnetic fields. Record all nameplate information for the induction motor. All you need is to plug the motor into an ac power supply and the motor. Multiple choice question mcq of induction motors page6. Ac induction motors are also the most common motors used in main powered home appliances.
The rotor will constantly be turning to align its magnetic field with that of the stator field. Introduction types of electrical machines types of 3 ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. Three phase induction motor mcq questions answers electrical. Lecture 6 three phase induction motors cairo university. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. The three phase induction motor is the extensively used for various kinds of industrial drives. When the rotor of 3 phase induction motor run at synchronous speed, its rotor frequency will become a. The method which can be used for the speed control of induction motor from stator side is a. Various automation processes in the industry need control of ac induction motors using ac drives.
An induction motor or asynchronous motor is an ac electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. Explain starting methods of 3 phase induction motor. Understand the principle and the nature of single phase and 3 phase induction machines. One motor is the called the main motor, and another motor is called the auxiliary motor. Types of ac motor definition and classification of ac motor. These are of two types, squirrel cage and slip ring motors. Stardelta starter connection for 3phase induction motor tamil vijayakrishna vk learn in. A three phase induction motor consists of two parts stator the stationary part and rotor. A capacitor start single phase induction motor will usually have a power factor of 0.
Construction of three phase induction motor electrical4u. But at the starting of the induction motor, starting current is very large which may damage motor windings. Introduction this application note describes the design of a 3 phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Controlling number of stator poles to control n s c.
Single phase induction motor multiple choice questions mcq. A three phase ac induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. Here we will see a detailed article related to the starting methods of three phase induction motor. A 2200v,50 hz, three phase,6 pole,yb connected squirrel cage induction motor has following parameters. The operation of an induction motor depends upon the creation of a rotating magnetic field. Apr 11, 2020 ssc je electrical important mcq pdf part 3 notedownload link of pdf given at end of post 1. When a three phase induction motor connected to a single phase power supply. You should also make a dc measurement of stator winding linetoline resistance.
At the end of the lecture, student should be able to. An induction motors rotor can be either wound type or squirrelcage type. A 3 phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Three phase flange mounted ac induction motors dimensions is 2223 60072 1 specification for energy efficient three phase induction motoris 12615 class of insulation is 1271 60085 conformance to standards. We arrange the three phase winding in such a manner in the slots that they produce one rotating magnetic field when we switch on the three phase ac supply source. Calculate ithe time taken and energy dissipated in the motor during starting. Speed control in three phase induction motor mcqs with answers q1. Controlling 3phase induction motors using vfd and plc. 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. When the 3 phase supply is provided to the stator, a magnetic field is produced which rotates the rotor and motor starts.
A 3 phase induction motor stator delta connected, is carrying. Ac introduction motors have been used in traction applications for a. An induction motor can therefore be made without electrical connections to the rotor. 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. 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. 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. If the frequency of 3 phase supply to the stator of 3 phase induction motor is increased, then. The rotor or stator slot of the induction motor skewed through some angle so that the bars lie under alternate harmonic poles of the same polarity or other words, bars must be skewed through two pitches. Induction motor objective questions with answers objectivebooks. 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. Speed control of three phase induction motor electrical4u. There are two basic reasons for the use of single phase motors rather than 3 phase motors.
Nov 27, 2019 the stator of three phase induction motor is made up of numbers of slots to construct a 3 phase winding circuit which we connect with 3 phase ac source. Perform an analysis on induction machines which is the most rugged and the most. This induces an electric field in a coil or squirrel cage to drive a rotor. An induction motor which connects with a 3 phase supply called 3 phase induction motor. Single phase induction motors multiple choice questions. Starting method for induction motors a 3 phase induction motor is theoretically self starting. Single phase induction motor and three phase induction motor. So when 3 phase ac supply is given to the stator windings of the induction motor, rmf revolving magnetic field is produced, that links with the conductor of cage rotor and produces emf, so a current start flowing through the conductors, hence torque is developed which causes the rotor to rotate. Speed control in three phase induction motor mcqs with answers. Oct 11, 2016 single phase motors part one instructions. Flexible 5 ratings correspondence 220380415v50hz,220440v60hz is standard. The main drawback of dc motors is the presence of commutator and brushes, which require frequent maint. Most important mcq or objective questions on induction motor are discussed in this page.
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