Electrical Machines Cogging of induction motor occurs at low voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are not equal. 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. Any of above method. Ward Leonard control. None of above. Rheostatic control. Any of above method. Ward Leonard control. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If B is flux density, l the length of the conductor and v the velocity of the conductor, then emf is given by Blv. Blv2. Bl2v2. Bl2v. Blv. Blv2. Bl2v2. Bl2v. 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 173 A. 240 A. 127 A. 190 A. 173 A. 240 A. 127 A. 190 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will be doubled. It will remain the same. It will becomes four times. It will be halved. It will be doubled. It will remain the same. It will becomes four times. It will be halved. ANSWER DOWNLOAD EXAMIANS APP
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