Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 25 Hz. 60 Hz. 16.67 Hz. 50 Hz. 25 Hz. 60 Hz. 16.67 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine, the armature windings are placed on the rotor because of necessity for electromechanical energy conversion. development of torque. commutation. generation of voltage. electromechanical energy conversion. development of torque. commutation. generation of voltage. 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 2, 3, 6 2, 4, 5, 6 1, 2, 5 3, 4, 5 2, 3, 6 2, 4, 5, 6 1, 2, 5 3, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which 1 - Φ motor does operate at high power factor? Split phase. Capacitor run. Shaded pole. Capacitor start. Split phase. Capacitor run. Shaded pole. Capacitor start. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these In case of any sparking they will be less damaged than copper brushes They are self lubricating in nature They are not hard as copper brush All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the purpose of starting an induction motor, star/delta switch is an equivalent to auto transformer of ratio 66.3% 57.7% 50% 33.3% 66.3% 57.7% 50% 33.3% ANSWER DOWNLOAD EXAMIANS APP
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