Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 44 A. 400 A. 440 A. 40 A. 44 A. 400 A. 440 A. 40 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A delta/star transformer is connected in parallel to a star/delta transformer. The turn ratio former is x times latter, the x is 1/3 3 1/√3 √3 1/3 3 1/√3 √3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 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 efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 78.5% 82.5% 72.5% 67.5% 78.5% 82.5% 72.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 400 V, 50 Hz, 30 Hp, three phase IM is drawing 50 A current at 0.8 p.f lagging. The stator and rotor copper losses are 1.5 KW and 900 W respectively. The friction and windage losses are 1050 W and core losses are 1200 W. The air gap power of the motor will be 25 kW. 26.21 kW. 24.11 kW. 23.06 kW. 25 kW. 26.21 kW. 24.11 kW. 23.06 kW. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchorous generator connected to an infinite bus is over excited. Considering only the reactive power from the point view of the system the machine acts as A capacitor. A resistor. an inductor. None of these. A capacitor. A resistor. an inductor. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The teeth in the armature of a DC machines are sometimes skewed. This is done to reduce eddy electric current loss. copper loss. hysteresis loss. vibrations. eddy electric current loss. copper loss. hysteresis loss. vibrations. ANSWER DOWNLOAD EXAMIANS APP
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