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 2.5Hz 1.5Hz 51.5Hz 48.5Hz 2.5Hz 1.5Hz 51.5Hz 48.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a star - delta starting of an IM applied voltage per stator phase is 57.7 % of a line volt line voltage is 57.7 % of stator voltage. resistance is inserted in the rotor. reduced voltage is applied to the stator. applied voltage per stator phase is 57.7 % of a line volt line voltage is 57.7 % of stator voltage. resistance is inserted in the rotor. reduced voltage is applied to the stator. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. Find the speed of stator magnetic field with respect to rotor? 1470 rpm 30 rpm 1500 rpm zero 1470 rpm 30 rpm 1500 rpm zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
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 mechanical losses. to reduce hysteresis loss. to provide better flux linkage. to reduce eddy current loss. to reduce mechanical losses. to reduce hysteresis loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating winding is placed in the pole shoe main field armature core All of these pole shoe main field armature core All of these ANSWER DOWNLOAD EXAMIANS APP
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