Electrical Machines Satisfactory commutation of DC machine requires All of these brushes should smoothly run in the holders. smooth, concentric commutator properly undercut. brushes should be of proper grade and size. All of these brushes should smoothly run in the holders. smooth, concentric commutator properly undercut. brushes should be of proper grade and size. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the operating region of slip in a 1-phase induction motor? 0 < S < 1 0 < S < 2 -1 < S < 1 -2 < S < 2 0 < S < 1 0 < S < 2 -1 < S < 1 -2 < S < 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero Eb is zero, but Td is unchanged both Eb and Td are unchanged both Eb and Td are zero Eb is unchanged, but Td is zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines On what factors the speed of dc motor depends? Field flux. Applied voltage. All of these. Armature current Ia. Field flux. Applied voltage. All of these. Armature current Ia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a DC series motor is Proportional to the armature current. Inversely proportional to the armature current. Proportional to field current. Proportional to the square of the armature current. Proportional to the armature current. Inversely proportional to the armature current. Proportional to field current. Proportional to the square of the armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque the flux waveform is improved with reduction in harmonics a counter-emf is induced in the coil undergoing commutation the inequality of air-gap flux on the top and bottom halves of the armature is removed ANSWER DOWNLOAD EXAMIANS APP
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