Electrical Machines The armature core of the rotor bars of dc motors are laminated to provide better flux linkage. to reduce eddy current loss. to reduce hysteresis loss. to reduce mechanical losses. to provide better flux linkage. to reduce eddy current loss. to reduce hysteresis loss. to reduce mechanical losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If any two leads from slip rings are interchanged in a 3 - Φ induction motor, the motor will continue running in the same direction as before. run in a direction opposite to previous one. get damaged. not run. continue running in the same direction as before. run in a direction opposite to previous one. get damaged. not run. 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% 82.5% 67.5% 72.5% 78.5% 82.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC generator rotates at 1500 rpm. How many times in a second, will the emf induced in each armature conductor changes its direction? 200. 750. 100. 500. 200. 750. 100. 500. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50Hz, the emf in the rotor will have a frequency of 51.5Hz 48.5Hz 2.5Hz 1.5Hz 51.5Hz 48.5Hz 2.5Hz 1.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the phase difference between two windings of A.C servomotor ? 90°. 30°. 60°. 120°. 90°. 30°. 60°. 120°. ANSWER DOWNLOAD EXAMIANS APP
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