Electrical Machines The principle of operation of a 3 - Φ induction motor is almost similar to that of synchronous motor. transformer with secondary short circuited. repulsion start induction motor. capacitor start induction motor. synchronous motor. transformer with secondary short circuited. repulsion start induction motor. capacitor start induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs None of these decrease. increase. either of these. None of these decrease. increase. either of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is 2, 3, 6 2, 4, 5, 6 1, 2, 5 3, 4, 5 2, 3, 6 2, 4, 5, 6 1, 2, 5 3, 4, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For very sensitive and wide speed control, the preferable control method is Multiple voltage control. Armature control. Field control. Ward-Leonard control. Multiple voltage control. Armature control. Field control. Ward-Leonard control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 38.5 Nm. 27.73 Nm . 74 Nm. 65.8 Nm. 38.5 Nm. 27.73 Nm . 74 Nm. 65.8 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The constant losses in transformer is/are hysteresis loss. eddy current loss. both 2 and 3. copper loss. hysteresis loss. eddy current loss. both 2 and 3. copper loss. ANSWER DOWNLOAD EXAMIANS APP
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