Electrical Machines In DC motors, under trailing pole tips, flux density will_______ ? either increase or decrease increase None of these decrease either increase or decrease increase None of these decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is used for the _______ ? below rated speed above rated speed both 1 and 2 None of these below rated speed above rated speed both 1 and 2 None of these 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%. 82.5% 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft torque of a dc motor is less than the electromagnetic torque because of eddy current losses. ohmic losses. mechanical losses. hysteresis losses. eddy current losses. ohmic losses. mechanical losses. hysteresis losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Unity power factor. Lagging power factor. Leading power factor. Zero power factor. Unity power factor. Lagging power factor. Leading power factor. Zero power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature coil is short circuited by brushes when it lies along neutral axis. along field axis. in any of above positions. in none of above positions. along neutral axis. along field axis. in any of above positions. in none of above positions. ANSWER DOWNLOAD EXAMIANS APP
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