Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 16.67 Hz. 60 Hz. 25 Hz. 50 Hz. 16.67 Hz. 60 Hz. 25 Hz. 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 3, 4, 5 2, 4, 5, 6 1, 2, 5 2, 3, 6 3, 4, 5 2, 4, 5, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To get the speed of DC motor is more than normal without wastage of electrical energy _____________ is used. Rheostatic control. None of above. Ward Leonard control. Any of above method. Rheostatic control. None of above. Ward Leonard control. Any of above method. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under trailing pole tips in case of generator 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 A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to 190 A. 127 A. 173 A. 240 A. 190 A. 127 A. 173 A. 240 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The torque angle, in a synchronous motor, is the angle between the rotating stator flux and rotor flux. None of these magnetizing electric current and back emf. the supply voltage and the back emf. the rotating stator flux and rotor flux. None of these magnetizing electric current and back emf. the supply voltage and the back emf. ANSWER DOWNLOAD EXAMIANS APP
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