Electrical Machines Hysteresis loop represents the area of hysteresis loss copper loss eddy current loss total iron losses hysteresis loss copper loss eddy current loss total iron losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 920 RPM 940 RPM 970 RPM 960 RPM 920 RPM 940 RPM 970 RPM 960 RPM 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 Woud be equal to 2If1. Would be equal to If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1. Would be equal to If1/2. Cannot be predicted due to insufficient data. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 volt dc motor has an armature winding resistance of 0.5 ohm. Calculate the emf induced by the motor if the full load armature current is 23 ampere. 220.4 volt. None of these. 120 volt. 218.5 volt. 220.4 volt. None of these. 120 volt. 218.5 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines 1 KVA, 230 V, 50 Hz, single phase transformer has an eddy current loss of 30 watts. The eddy current loss when the transformer is excited by a dc source of same voltage will be more than 30 W less than 30 W 30 W zero watt more than 30 W less than 30 W 30 W zero watt ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronising power of a synchronous motor varies inversely as 1/Xs directly as synchronous reactances Xs directly as Xs2 All of these inversely as 1/Xs directly as synchronous reactances Xs directly as Xs2 All of these ANSWER DOWNLOAD EXAMIANS APP