Electrical Machines Field weakening control method is used for the _________ ? below rated speed both A and B above rated speed None of these below rated speed both A and B above rated speed None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, the ripples in the direct emf generated are reduced by employing carbon brushes. equalizer rings. graphite brushes. commutator with large number of segments. carbon brushes. equalizer rings. graphite brushes. commutator with large number of segments. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For satisfactory parallel operation of two transformers which of the following conditions is most essential, polarities of all transformers must be same. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. polarities of all transformers must be same. voltage ratio of all transformers must be same. percentage impedance of all transformers must be same. MVA rating of all transformer inversely proportional to impedance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Scott connections are used for any of the above. three phase to two phase transformation. three phase to single phase transformation. single phase to three phase transformation. any of the above. three phase to two phase transformation. three phase to single phase transformation. single phase to three phase transformation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 88.8%. 57.1%. 48.0%. 59.2%. 88.8%. 57.1%. 48.0%. ANSWER DOWNLOAD EXAMIANS APP
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