Electrical Machines To achieve spark less commutation brushes of DC generator are rocked ahead so as to bring them in magnetic neutral axis. None of these just behind the magnetic neutral axis. just ahead of magnetic neutral axis. in magnetic neutral axis. None of these just behind the magnetic neutral axis. just ahead of magnetic neutral axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, which of these parameters remain the same whether it runs as a DC motor or a DC generator? Induced emf. Can not be determined. Armature current. Mechanical power. Induced emf. Can not be determined. Armature current. Mechanical power. 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 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of the dc motor is generally of the range 100 ohm. 0.1 ohm. 50 ohm. 0.5 ohm. 100 ohm. 0.1 ohm. 50 ohm. 0.5 ohm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines No load test on induction motor is conducted to find which of the following losses? Stator core loss Rotational loss All of these Stator copper loss Stator core loss Rotational loss All of these Stator copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator has full-load voltage regulation of 10% at rated speed of 1000 rpm. If it is now driven at 1250 rpm, then its voltage regulation at full load would be more than 10% remain unchanged be less than 10% be 12.5% be more than 10% remain unchanged be less than 10% be 12.5% ANSWER DOWNLOAD EXAMIANS APP
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