Electrical Machines A small air gap in poly phase induction motor helps to reduce magnetizing current. reduce chance of crawling. reduce chance of cogging. increase starting torque. reduce magnetizing current. reduce chance of crawling. reduce chance of cogging. increase starting torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by KhfBm. Khf2Bm1.6. KhfBm3. KhfBm1.6. KhfBm. Khf2Bm1.6. KhfBm3. KhfBm1.6. 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 3, 4, 5 1, 2, 5 2, 3, 6 2, 4, 5, 6 3, 4, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronous reactance of an alternator represents a reactance operating at synchronous speed armature reactance and leakage reactance All of these field winding reactance a reactance operating at synchronous speed armature reactance and leakage reactance All of these field winding reactance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to an induction motor, the air gap in a DC motor is more. between 50% and 90%. less than 50%. same. more. between 50% and 90%. less than 50%. same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip speed is the difference of synchronous speed and actual rotor speed. difference of actual rotor speed and synchronous speed. sum of synchronous and rotor speeds. half of the sum of synchronous and rotor speeds. difference of synchronous speed and actual rotor speed. difference of actual rotor speed and synchronous speed. sum of synchronous and rotor speeds. half of the sum of synchronous and rotor speeds. ANSWER DOWNLOAD EXAMIANS APP
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