Electrical Machines Objective Questions

Electrical Machines Questions & Answers

1. Magnetic Circuits

• Principle of Energy Conversion

• Excited Magnetic Systems

2. Basic Concepts in Rotating Machines

• Reluctance Motor

• Doubly Excited Magnetic Systems

• Elementary Synchronous Machines

• Singly Excited Electric Field Systems

• Torque Production and Dynamic Equations

• Terms Pertaining to Rotating Machines

• Rotating Magnetic Field – 1

• Rotating Magnetic Field – 2

3. Constructional Features of Rotating Electrical Machines

• Features of Rotating Electrical Machines-1

• Features of Rotating Electrical Machines-2

• Features of Rotating Electrical Machines-3

4. Principles of Electro mechanical Energy Conversions

• Generated Emfs

5. Rating and Loss Dissipation

• Losses and Efficiency – 1

• Losses and Efficiency – 2

• Machine Ratings

• Cooling(Loss Dissipation)

6. Electrical Machine Applications/ Armature Reaction and Commutation

• Machine Applications

• Action of Commutator

7. Electromechanical Energy Conversions

• EMF Generated in the Armature

• Torque in DC Machines

8. DC Machines

• Circuit Model of DC Machines

• Methods of Excitation

• MMF and Flux Density Waveforms in DC Machines

• Effect of Brush Shift and Compensation Windings

• Efficiency and Testing of DC Machines

• DC Machine Applications

9. DC Generators

• Operating Characteristics of DC Generators

• Rotating Amplifiers

10. DC Motors

• Operating Characteristics of DC Motors

• DC Motor Starting

• Speed Control of DC Motors

• Permanent Magnet DC (PMDC) Motors

11. Synchronous Machines

• EMF Polygon – 1

• EMF Polygon – 2

• Production of Torque in Non-Salient Pole Machines

• MMF Produced by Distributed Windings

• Excitation Systems for Synchronous Machines

• Flux and MMF Phasors in Synchronous Machines

• Physical Concepts of Synchronous Machine Operation

• Power Factor Control of Synchronous Machines

• Two Reaction Theory of Salient Pole Machines

• Power Angle Characteristics of Synchronous Machines

• Measurement of Xd and Xq

• Synchronous Machine Applications

12. Synchronous Generators

• Phasor Diagram of a Cylindrical Rotor Alternator

• Voltage Regulation of an Alternator

• Operating Characteristics of Alternators and their Ratings

13. Synchronous Motors

• Synchronous Motor Phasor Diagram

• Power Factor Correction by Synchronous Motors

• Starting of Synchronous Motors

14. Efficiency and Regulation

• Power Flow Through an Inductive Impedance – I

• Power Flow Through an Inductive Impedance – II

• Efficiency of Synchronous Machines

• Losses and Efficiency

15. Synchronous Machine Stability

• Synchronizing Power and Synchronizing Torque

• Synchronous Machine Stability

• Hunting and Damper Windings

16. Induction Machines

• Induction Motor as a Transformer

• Principle of Operation

• Flux and MMF Phasors and Waves in Induction Motors

• Rotor Frequency

• Rotor EMF, Current and Power

• Induction Motor Phasor Diagram

• Equivalent Circuit

• Analysis of the Equivalent Circuit

• Operating Characteristics of Induction Motors

• Determination of Equivalent Circuit Parameters

• Power Factor Control of Three Phase Induction Motors

• Induction Generator

• Applications of Polyphase Induction Motors

• Circle Diagrams of Induction Machines

17. Starting of Induction Motors

• Starting of Polyphase Induction Motors-I

• Starting of Polyphase Induction Motors-II

18. Armature Windings

• Armature Windings

19. Transformers

• Transformer Construction

• Ideal Two Winding Transformer

• Transformer Phasor Diagram

• Equivalent Circuit of Transformer

• Open Circuit and Short Circuit Test

• Voltage Regulation of Transformer

• Transformer Losses and Efficiency

• Parallel Operation of Single Phase Transformers

• Transformer as a Magnetically Coupled Circuit

• Three Phase Transformers

• Autotransformers