Electrical Machines Maximum efficiency will occur, when copper loss is_______to iron loss? less than equal to greater than any of the above less than equal to greater than any of the above ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two 3-phase AC generators are such that one has twice the linear dimensions of the other. The field windings of each are excited to give identical sinusoidal air-gap flux density waveform. Both have the same number of stator slots and identical winding patterns. The conductor/slot in a big generator is K times that of the smaller one. The value of K to get equal no load voltage at same frequency is 1/4. 1/2. 4. 8. 1/4. 1/2. 4. 8. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor is, in general analogous to auto transformer. None of these two winding transformer with secondary short circuited. two winding transformer with secondary open circuited. auto transformer. None of these two winding transformer with secondary short circuited. two winding transformer with secondary open circuited. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 3, 5 2, 3 , 5 1, 4 2, 4 ,5 1, 3, 5 2, 3 , 5 1, 4 2, 4 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In large sized DC machines the compensating windings are provided to reduce eddy current losses by providing local short circuits. None of these neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. reduce eddy current losses by providing local short circuits. None of these neutralize voltage induced in coil due to fluctuation of l compensate for the decrease in speed due to increase of load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the armature circuit. Inserting an additional resistance in the field circuit. Inserting resistance to armature circuit and field circuit. ANSWER DOWNLOAD EXAMIANS APP
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