Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor Decrease. Remains same. Increase. None of these. Decrease. Remains same. Increase. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Unbalance 3 - Φ stator currents cause vibrations. heating of rotor. All of these double frequency currents in the rotor. vibrations. heating of rotor. All of these double frequency currents in the rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Lagging power factor. Unity power factor. Zero power factor. Leading power factor. Lagging power factor. Unity power factor. Zero power factor. Leading power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the maximum power factor of an induction motor for dispersion coefficient of 0.05? 0.05. 0.905. 1.1. 20. 0.05. 0.905. 1.1. 20. 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%. 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% 82.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators brushes are used for collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings ANSWER DOWNLOAD EXAMIANS APP
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