also we can provide Electrical objective questions books & Interview questions. This list is mainly about Multiple Choice Questions (MCQs) on DC Machines. 9. bearings. Define the term commutation in dc machines. Armature. Armature current, Ia = (V-En)/Ra, where V= applied voltage and Ra= armature resistance. C and D only 3. Popular topic for study. Following Electrical Engineering Multiple choice objective type questions and answers will help you in BSNL JTO, GATE 2020 and IES 2020 examinations : 1.In a D.C. shunt motor, speed is. 50 Common Interview Questions and Answers Page 8 of 25 9. A DC motor is a mechanically commutated electric motor powered from direct current (DC). 1. Pick a real example (make sure it’s not about someone working in the company you want to join), but be discreet about the person’s identity. Commutator. What is the value of Nr when S=0.6, Ns=1000RPM A)400 RPM B)500 RPM C)600 RPM D)700RPM ANSWER:A 25. In this unit, we will look at two major forces that machines help us overcome — friction and gravity. 3/23/2007 ELEC A6 DC Machine 9 DIRECT CURRENT MACHINES DC machine Construction • The rotor iron core is mounted on the shaft. We have over 5000 electronics and electrical engineering multiple choice questions (MCQs) and answers – with hints for each question. It consists of several copper segments, separated by insulation. 6. armature windings. How and why the compensating winding in dc machine excited? DC Motor or Direct Current Motor Multiple Choice Questions and Answers. Network Admittance and impedance matrices . machines, and these appear somewhat more complicated but in reality are combi-nations of the three basics. 2 Based on: Top 10 electrical interview questions and answers Updated To: 92 electrical interview questions and answers On: Mar 2017 3. On the other hand, the bus impedance matrix is equally well favored for power system fault analysis. Poles. Professionals, Teachers, Students and Kids Trivia Quizzes to test your knowledge on the subject. Inertia, on the other hand, is a characteristic of matter — it is the resistance of mass to being in motion or removed from motion. 7. interpoles . Next » This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “DC Motor Basics -1”. The bus admittance matrix is widely used for power-flow analysis. Latest D.C. Generators Interview Questions and Answers List 1. 3. PLC Interview Questions and Answers. 4. Dear Readers, Welcome to Electrical Machines multiple choice questions and answers with explanation. What is the value of frequency when Ns=1000 RPM , P=6 A)30Hz B)40Hz C)50Hz D)60Hz ANSWER:C 24. Here are the types of questions on electric motors which are asked in an interview, question papers and other competitive exams as well. So, we have covered all the possible sections of dc machines. • Note the commutator mounted on the shaft. These objective type Electrical Machines questions are very important for campus placement test, semester exams, job interviews and competitive exams like GATE, IES, PSU, NET/SET/JRF, UPSC and diploma. Answer 1. • The field winding is on the stator and is excited by direct current. 5. pole shoes. C. Reduce armature copper loss. CLICK HERE —-> EEE INTERVIEW QUESTIONS. Slip When Nr=Ns A)1 B)0 C)0.5 D)0.4. Reduce the eddy-current loss. Home >> Category >> Electrical Engineering (MCQ) questions and answers >> Synchronous Machines; 1) Generally, in alternator divided winding rotor is preferred to a conventional winding rotor, because it gives. Brushes. What is the difference between earth resistance and earth electrode resistance? Network Theorems 3. 74. 8. Electrical Machines MCQ Quiz Multiple Choice Questions and Answers. You need to then take useful information from this operating condition and apply it to the new operating conditions specified in the rest of the question. Important Questions On Electrical Machines PDF Download; Results 1 to 6 of 6 . ANSWER:B 23. • The end of the coils are bent and tied together to assure mechanical strength. 1. D only 2. Elementary DC Machines • The armature winding of a dc generator is on the rotor with current conducted from it by means of carbon brushes. To reduce the Harmonic in generated EMF. 3 This ebook consists of two parts: - Part I: 92 electrical interview questions and answers (pdf, free download) - Part II: … Your name: Your Email: Your Comments: … This is how the relative angle between the stator and rotor magnetic flux is maintained near 90 degrees, which generates the maximum torque. The Chapters of Multiple Choice Questions (MCQs) on DC Machines. >The presence of back emf (Eb) or counter emf makes the dc motor a self regulating machine, i.e. PLC MCQ, Programmable Logic Controllers Examples, PLC Programs, PLC Tutorials, PLC Ladder Logics, PLC Theory. Thread: Important Questions On Electrical Machines PDF Download. B. 18. The current in the rotor is switched by the commutator to also be stationary in space. 10. shaft . Magnetic frame or yoke. Current Electricity 2. D.Reduce the eddy-current loss Your Comments. 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. it makes the motor to draw as much armature current as is just sufficient o develop the torque required by the load. Multiple Choice Questions with Answers on DC Generators - Set 08 MCQ DC Generators Edit Practice Test: Question Set - 08. This question is similar to many DC machine questions and falls into two parts. Q. Electrical Machines Objective Question and Answer to prepare for competitive and entrance exams and test your skills on the topic. 130 TOP DC MOTOR Objective Questions Answers pdf free Download. 123 TOP D.C. Motors - Electrical Engineering Multiple Choice Questions and Answers The changes that take place in winding elements during the period of short circuit by a brush is called commutation. What is the purpose of yoke in d.c machine? A: 1. A Single-phase autotransformer is a single winding transformer in which a part of the winding is common to both high-voltage and low-voltage sides. Show / Hide Solution. 1) What is a single phase Autotransformer? For example, we have covered, the working principle of dc motors and working principle of dc generators. a. No-load speed of which of the following motor will be highest? What will happen if the back e.m.f. • Coils are placed in the slots. Average marks 1.71. Specially developed for the Electrical Engineering freshers and … The armature of DC machine is made up of laminated sheets to ..... A. Laminations of core are generally made of (a) case iron (b) carbon (c) silicon steel (d) stainless steel Ans: c At the start of the question, you are given a reasonable amount of data about a specific operating condition. In this chapter, we concentrate on conventional synchronous machines whereas the brushless dc motors will be discussed later in a separate chapter. This video provides all the important mcq questions of dc motor in detail and also provides some important points to remember for interviews and exams. You will get all the DC Motor MCQ Important Question and Answer with Explanation for your all electrical Engineering competitive Exams.. 1. 75. Below are the list of all Electrical Engineering Multiple Choice Questions and Answers for EEE students. What will happen if DC shunt motor is connected across AC supply? Dec 21, 2016 - Electrical Machines Objective Type Questions and Answer-PDF for Competitive Exams,electric dc machines motor mcqs questions and answers So answer it with a mix of honesty, diplomacy and positivity. 21. Tell me about your worst boss. Thus a dc motor adjusts its input automatically to match the load on the shaft. Electric Motors are the machines that convert electrical energy into the mechanical energy which further is used to drive a vehicle, plant and many more things around us. Synchronous Machines - Electrical Engineering (MCQ) questions and answers. The topics that are covered in this PDF containing Electrical Machines Year GATE Solved Questions are: Single phase transformer: equivalent circuit, phasor diagram, open circuit and short circuit tests, regulation and efficiency; Three phase transformers: connections, parallel operation; Auto‐transformer, Electromechanical energy conversion principles, DC machines: separately excited, … 1. multiple machines to be locked out by the turn of a single key switch. Electrical Engineering Questions with Answers pdf :-1. Less harmonics c. More efficiency d. None of these. Synchronous Machine Structures Stator and Rotor The armature winding of a conventional synchronous machine is almost invariably on the stator and is usually a three phase winding. (c) 2. The output power of any electrical motor is taken from the (a) Armature (b) Field (c) Coupling mounted on the shaft (d) Motor frame Ans. The stator is stationary in space by definition and therefore so is its current. Home » D.C.MOTORs Questions » 130 TOP DC MOTOR Objective Questions Answers pdf free Download. 2. Total 28 Questions have been asked from DC Machines: Separately Excited, Series and Shunt, Motoring and Generating Mode of Operation and Their Characteristics, Starting and Speed Control of DC Motors topic of Electrical Machines subject in previous GATE papers. Answer: Only one of the terminals is evident in the earth resistance. of a D.C. motor vanishes suddenly? Solution. Explanation: In full pitched coils, as one conductor of a turn in a coil cuts N pole, the other conductor of the same turn cuts S pole resulting in the production of induced emf(E), i.e phase angle is 180 degree (a) The motor will stop (b) The motor will continue to run (c) The armature may burn (d) The motor will run noisy Ans: c. 22. (b) A commutator is necessary as part of a DC generator to produce unidirectional voltage at the terminals of the generator (c) The field winding of a DC machine is housed in slots on the armature (d) The brushes of a DC machine are usually made of carbon and do not rotate with the armature Options: 1. DC MACHINE QUESTION AND ANSWER Q: What are the essential parts of DC machine? a) Will run at normal speed b) Will not run c) Will Run at lower speed d) Burn due to heat produced in the field winding View Answer. 1.It acts as a protecting cover for the whole machine and provides mechanical support for the poles. Reduce hysterisis loss . A list of top frequently asked Electrical Machines interview questions and answers are given below. This is a tricky question. Electrical Engineering : Dc Motors QUESTIONS AND ANSWERS :: part1 : 1 to 5. D. Increase dissipation of heat from the armature surface View Answer . Better damping b. DC Machines Questions and Answers – DC Motor Basics -1 « Prev. ANSWER:B. CLICK HERE TO DOWNLOAD 25 QUESTIONS PDF • In a dc machine, the armature winding is found on the rotating member, referred to as the rotor.