Electrical Machines A 3-phase, 50Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor output power? 1920W 1450W 1820W 2000W 1920W 1450W 1820W 2000W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc motors, under leading pole tips flux density will--------? increase None of these decrease either increase or decrease increase None of these decrease either increase or decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to None of these compensate for the decrease in speed due to increase of load. neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. None of these compensate for the decrease in speed due to increase of load. neutralize voltage induced in coil due to fluctuation of l reduce eddy current losses by providing local short circuits. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1/2. Would be equal to If1. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1/2. Would be equal to If1. 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 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the flux of DC motor approaches zero, its speed will remain unchanged. approach zero. between zero and infinity. aprroach infinity. remain unchanged. approach zero. between zero and infinity. aprroach infinity. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS