Electrical Machines At the instant of starting, the per unit slip of 3 - Φ induction motor is 0.05. 0.5. 0.1. 1.0. 0.05. 0.5. 0.1. 1.0. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of a DC motor is laminated to reduce copper loss. friction and windage loss. eddy current loss. hysteresis loss. copper loss. friction and windage loss. eddy current loss. hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.95 1.06 0.96 0.87 0.95 1.06 0.96 0.87 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%. 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of supply frequency. Change of number of pole. Change of rotor resistance. Change of supply voltage. Change of supply frequency. Change of number of pole. Change of rotor resistance. Change of supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3000 rpm. 500 rpm. 600 rpm. 3600 rpm. 3000 rpm. 500 rpm. 600 rpm. 3600 rpm. ANSWER DOWNLOAD EXAMIANS APP