This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Machine Ratings”. 1. Refer the diagram; a single-phase supply of 100V, 50Hz is fed to the step-up transformer having primary impedance of 1 ohms and secondary impedance 20 ohms. What is the power consumed by the load of 5 ohms? a) 20 … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Losses and Efficiency – 2”. 1. A consideration of the power losses in electrical machines is essential for which of the following reasons? a) Operating cost b) Temperature rise c) Voltage drops d) All of the mentioned 2. To determine the efficiency … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Losses and efficiency”. 1. For the given traction application using a dc series motor for a starting time ’t’ is applied. If this method is replaced by a series-parallel control, giving 50% time for each series and parallel. The saving in the … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Generated EMF”. 1. Which of the following statements is/are correct regarding the generation of EMF in rotating electrical machines in the armature winding? EMF is generated ____________ a) by rotating armature windings through a magnetic field b) by rotating magnetic field with … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Constructional Features of Rotating Electrical Machines-3”. 1. How many poles should the alternators, driven by the steam and gas turbines prime movers must have, for better operation? a) fewer number of poles b) large number of poles c) medium number of poles … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Constructional Features of Rotating Electrical Machines-2”. 1. Which type of slots are used in the construction of large size and small size induction motors respectively? a) open slots and semiclosed slots b) semiclosed slots and open slots c) open slots and open … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Constructional Features of Rotating Electrical Machines-1”. 1. Which of the following two windings produces/induces the working flux and working EMF respectively? a) field winding and armature winding b) armature winding and field winding c) both are produced in field winding d) both … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Rotating Magnetic Field – 2”. 1. If F1 is the constant amplitude of fundamental rotating MMF wave, the for the space harmonics of order 6K-1 (where K=1,2,3….), the harmonic MMF wave is of _____________ a) Constant amplitude and stationary in space b) … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Rotating Magnetic Field – 1”. 1. For a p-pole machine, which of the following statements are correct regarding the rotating field speed? a) The rotating field speed is 1/(p/2) revolutions in one cycle b) f/(p/2) revolutions in f cycles c) f/(p/2) revolutions … Read more
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Terms Pertaining to Rotating Machines”. 1. For a P-pole machine, the relation between electrical and mechanical degrees is given by _____________ a) θelec = 2/P θmech b) θelec = 4/P θmech c) θmech = P/2 θelec d) θelec = P/2 θmech 2. … Read more
