Electrical Machines The armature shaft must be able to withstand twisting strains due to transmission of torque. bending moment due to weight of the armature. any unbalanced magnetic pull on the armature core. All of these twisting strains due to transmission of torque. bending moment due to weight of the armature. any unbalanced magnetic pull on the armature core. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The material used for commutator brushes is mostly mica. carbon. copper. cast iron. mica. carbon. copper. cast iron. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 3, 4, 5 2, 3, 6 1, 2, 5 2, 4, 5, 6 3, 4, 5 2, 3, 6 1, 2, 5 2, 4, 5, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The sparking at the the brushes, in a DC machines is due to high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. high resistance of carbon brushes. reactance voltage. armature reaction. presence of commutator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. increase in speed but armature currnet remains the same. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed demanding more armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series generators are used in which of the following applications? All of these Air crafts. Used as boosters in dc distribution or transmission. Arc welding. All of these Air crafts. Used as boosters in dc distribution or transmission. Arc welding. ANSWER DOWNLOAD EXAMIANS APP
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