Electrical Machines The leakage reactance of a 3-phase alternator is determined by performing open circuit and zero power factor tests. zero power factor and slip tests. short circuit and slip tests. open circuit and short circuit tests. open circuit and zero power factor tests. zero power factor and slip tests. short circuit and slip tests. open circuit and short circuit tests. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? All of these They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush All of these They are self lubricating in nature In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the operating region of slip in a 1-phase induction motor? 0 < S < 2 -1 < S < 1 0 < S < 1 -2 < S < 2 0 < S < 2 -1 < S < 1 0 < S < 1 -2 < S < 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be None of these 6% and -4% 3.2% and -1.6% 4.8% and -3.2% None of these 6% and -4% 3.2% and -1.6% 4.8% and -3.2% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The condition for maximum running torque is 0.5 lagging R = S.X zero unity 0.707 lagging 0.5 lagging R = S.X zero unity 0.707 lagging 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 960 RPM 940 RPM 970 RPM 920 RPM 960 RPM 940 RPM 970 RPM ANSWER DOWNLOAD EXAMIANS APP