This set of DC Machines Interview Questions and Answers for Experienced people focuses on “Commutation Process – 2”. 1. To achieve spark less commutation brushes of a DC generator are placed ________ a) just ahead of magnetic neutral axis b) in magnetic neutral axis c) just behind the magnetic neutral axis d) can be placed … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Commutation Process -1”. 1. Commutation is delayed due to __________ a) Leakage reactance b) Effect of armature reaction c) Leakage reactance and armature reaction d) Because of other factors 2. Why brushes shifting method is not employed in practical commutation? a) Expensive … Read more
This set of DC Machines Questions and Answers for Experienced people focuses on “Ways to Reduce Effects of Armature Reaction – 2”. 1. Axis undergo shifting as a result of armature reaction, can be balanced by ______ a) Increase in armature current b) Decrease in armature current c) Introducing interpoles d) Removing interpoles 2. The … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Ways to Reduce Effects of Armature Reaction – 1”. 1. The armature reaction in a DC machine causes distortion in the main field flux. Effect of armature reaction can be reduced by_________ a) Increasing the length of air gap b) Decreasing the … Read more
This set of DC Machines Interview Questions and Answers for freshers focuses on “Armature Reaction – 2”. 1. Flux density in the interpolar region drops down because of ______ a) ATa (peak) b) Large air gap c) Absence of magnetic poles d) Depends on other parameters 2. Resultant ampere-turn distribution of a DC machine is … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Armature Reaction -1”. 1. In a DC machine, the form of armature mmf waveform is __________ a) Triangular b) Sinusoidal c) Saw tooth d) Rectangular 2. In a DC machine, the direct axis is __________ a) Axes of main poles b) Axes … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Electromagnetic Power and Circuit Models”. 1. Product of torque and mechanical angular velocity ω is_____ a) Ea/ω b) Ea*Ia c) ω/Ea d) Can’t tell 2. Condition for linear magnetization is______ a) φ α If b) φ α Ia c) φ α 1/If … Read more
This set of DC Machines Questions and Answers for Freshers focuses on “EMF and Torque Production – 2”. 1. A 4-pole Dc wound machine is lap wound with 400 conductors. The pole shore is 20 cm long and average flux density over one-pole pitch is 0.4 T, the armature diameter being 30 cm. What is … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “EMF and Torque Production – 1”. 1. In which mode machine is operating, given that conductor current is in the same direction of conductor emf? a) Motoring b) Generating c) Can’t be determined using directions d) In both modes for different cycles … Read more
This set of DC Machines Multiple Choice Questions & Answers (MCQs) focuses on “Wave Winding”. 1. What will be the value of “Yf + Yb” for a wave winding? a) Equal to Yc b) Half of the Yc value c) Double of the Yc value d) Four times Yc value 2. For a progressive wave … Read more
