Objective polyphase induction motors questions and answers pdf. Expected three phase induction motor objective questions. Three phase induction motor introduction basic electrical. Why it is required to start 3 phase induction motors. A 3 phase induction motor stator delta connected, is carrying.
Here we will see a detailed article related to the starting methods of three phase induction motor. This document is highly rated by electrical engineering ee students and has been viewed 2470 times. Alternator multiple choice questions mcq and answers. Being in hindi makes easy to understand the electricity. Three phase induction motors mcqs with explanatory answers 1. A 3 phase induction motor can be used for different applications with various speed and load requirements. This is a very useful website foe engineering students and those preparing electrical exam. The stating torque of the slip ring induction motor can be increased by adding. The method which can be used for the speed control of induction motor from stator side is a. 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.
The induction motor is fundamentally a transformer in which the stator is the primary and the rotor is shortcircuited secondary. There are two basic reasons for the use of single phase motors rather than 3 phase motors. Rotating flux is only possible when 3 phase voltage or poly phase which is 120 degree apart in time is applied to a three phase winding or poly phase winding 120 degree apart in space then a three phase rotating. Single phase induction motors mcqs electricalvoice. In a three phase induction motor a power factor at starting is high as compared to that while running. If the capacitor of a single phase motor is shortcircuited. Rotor of three phase induction motor consists of a cylindrical laminated core with parallel. A 3 phase slip ring motor has a double cage rotor 6 wound rotor c shortcircuited rotor d any of the above ans. Sep 02, 2014 101 top polyphase induction motors electrical engineering multiple choice questions and answers. 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. A three phase induction motor consists of two parts stator the stationary part and rotor. 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 split phase motor, the running winding should have a high resistance and low inductance b low resistance and high inductance c high resistance as well as high inductance d low resistance as well as low inductiance ans. But at the starting of the induction motor, starting current is very large which may damage motor windings.
List and describe the more commonly used equipment in an electric substation. Speed control in three phase induction motor mcqs with answers q1. Real time single phase induction motor interview questions with answers pdf also read induction motors mcqs 1. 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. Hindi three phase and single phase induction motors.
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. In three phase 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. The induction motor is started by itself that we know. While using stator resistance starter with 3 phase induction motor, the resistances of the starter are kept at a. Three phase induction motors mcqs with explanatory answers. Induction motor mcqs with answers set 02 objectivebooks. Here are contains the mcq, trade theory, technical exam objective question answe. The three phase induction motor is the most widely used electrical motor. Which of the following component is usually fabricated out of silicon steel. Construction of three phase induction motor electrical4u.
They run at a constant speed from noload to the full load. It is simple and rugged in construction it is relatively cheap induction motors. You should also make a dc measurement of stator winding linetoline resistance. Mostafa elshahed objectives learn a brief history of the electrical power systems construction. Three phase induction motor mcq questions answers electrical. When the 3 phase supply is provided to the stator, a magnetic field is produced which rotates the rotor and motor starts. Three phase ac circuits mcqs with explanatory answers. Home category electrical engineering mcq questions and answers 3 phase induction motors. Multiple choice questions on three phase induction motor free download as word doc. Then the motor a will continue running burning its one phase. Explain starting methods of 3 phase induction motor.
Three phase induction motors questions and answers sanfoundry. 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 1 phase i. Single phase induction motor multiple choice questions mcq. Multiple choice question mcq of induction motors page1. Objective polyphase induction motors questions and answers pdf 71. Polyphase induction motors mcq question is the important chapter for a electrical. The starting torque of a three phase induction motor can be increased by. If the frequency of 3 phase supply to the stator of 3 phase induction motor is increased, then. Most important mcq or objective questions on induction motor are discussed in this page. This course is about a brief explanation of single phase and three phase induction motors with their important questions.
Starting method for induction motors a 3 phase induction motor is theoretically self starting. 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. Induction motor important mcq questions part 1 youtube. 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. At zero in an induction motor a motor runs as a generator b motor does not run. Nov 27, 2019 the three phase induction motor is the most widely used electrical motor. Types of starters in three phase induction motor mcqs with answers q1. Apr 17, 2019 3 phase induction motor mcq pdf induction motor question bank rotor of three phase induction motor. Three phase ac circuits mcqs with explanatory answers 1. Single phase induction motors multiple choice questions. Handpicked mcq asked in interviews and gate exam from induction motor. If a single phase induction motor runs slower than normal, the most likely defect is a worn bearings b shortcircuit in the winding c opencircuit in the winding.
Electrical engineering three phase induction motor objective. Polyphase induction motors mcqs answers electrical engineering multiple choice questions answers pdf download. 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. M motor mcq three phase induction motor click here to download pdf of 3 phase i. Polyphase induction motors mcqs for preparation pakmcqs. 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. Jan 02, 2020 why is an induction motor selfstarting. Apr 12, 2020 ppt three phase induction motor electrical engineering ee notes edurev is made by best teachers of electrical engineering ee. One single phase wattmeter plus miscellaneous apparatus as needed. Polyphase induction motor mcq set 03 objectivebooks. Polyphase induction motors mcqs for preparation of fpsc, nts, kppsc, ppsc, and other test. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% will be. While using stator resistance starter with 3 phase induction motor, the resistances of.
Braking methods of 3 phase induction motor electrical. For explanatory answer, click on the toggle button labeled as check explanatory answer. A 3 phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Dec, 2018 electrical engineering three phase induction motor objective types question and answer in hindi in this video we know about 25 important 25 objective questions with their answer in hindi which. Three phase induction motor electrical engineering mcq questions answers. 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. The method which can be used for the speed control of induction motor from stator.
Most asked objective questions or mcq on single phase. Three phase ac circuits mcqs with explanatory answers three phase ac circuits mcqs with explanation. What are the advantages and disadvantages of induction motors. Induction motors interview questions and answers mcqs. Ppt threephase induction motor electrical engineering. The stator of an induction motor consists of 3 phase windings, which when connected to a 3 phase supply creates a rotating magnetic field. Types of starters in three phase induction motor mcqs with answers. Difference is that transformer is an alternating flux machine while induction motor is rotating flux machine. In this page you can learn various important synchronous motor multiple choice questions answers,synchronous motor mcq,sloved synchronous motor objective questions answers, synchronous motor mcq pdf etc. If the capacitor of a single phase motor is shortcircuited a the motor will not start b the motor will run c the motor will run in the reverse direction d the motor will run in the same direction at reduced r. When the supply frequency of a three phase induction motor is increased, then its synchronous speed is a decreases. Start induction motor dynamic and steadystate performance of a.
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. In this page you can learn various important alternator multiple choice questions answers,alternator mcq,sloved alternator objective questions answers, alternator mcq pdf etc. Multiple choice questions on three phase induction motor. Differentiate between the various types of generating electric power stations.
A 3 phase 440 v, 50 hz induction motor has 4% slip. Induction motor different types of duties in motor construction how induction motor as a rotating transformer how to run three phase motor on single phase power supply induction motor interview question slip ring induction motor srim vs squirrel cage induction motor scim synchronous watt types of encloser employed in induction motor types of insulation class. The main drawback of dc motors is the presence of commutator and brushes, which require frequent maint. Record all nameplate information for the induction motor. Latest automobile engineering multiple choice questions and answers pdf. This video provides all the important mcq questions from induction motor in detail and also provides some important points. The frame of an induction motor is usually made of a silicon steel b cast iron. Introduction types of electrical machines types of 3 ph induction motor basic principle working principle compnents of induction motor application comparision between 1ph i. This is provide je, technician, iti electrician, ac, dc, motor, generator, single phase and three phase. The three phase induction motors are simple in construction, rugged, low cost and easy to maintain. Single phase induction motors mcqs answers pdf electrical.
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. An induction motor which connects with a 3 phase supply called 3 phase induction motor. The starting torque of a 3 phase squirrel cage induction motor is a twice the full load torque b 1. Types of starters in three phase induction motor mcqs. The input power to a three phase induction motor is given by, p in 3 v ph i ph cos. Latest single phase induction motors questions and answers list 1. 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. When the rotor of 3 phase induction motor run at synchronous speed, its rotor frequency will become a. For reason of economy, most houses, offices and also rural areas are supplied with single phase a. 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. Synchronous motor multiple choice questions mcq and.
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