Electrical Machines Brushes are always placed on--------------- , in order to achieve sparkles commutation? GNA MNA None of these either GNA or MNA GNA MNA None of these either GNA or MNA ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic circuit of a dc shunt generator with negligible armature resistance and brush contact voltage drop remains unsaturated when it delivers full-load current at rated terminal voltage. The brushes are kept in the interpolar axis and speed is maintained constant. When the load is switched off, the terminal voltage would become zero increase decrease remain the same become zero increase decrease remain the same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 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 4. 8. 1/2. 1/4. 4. 8. 1/2. 1/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For 250 volt DC Shunt Motor the armature and field resistance are 0.5 ohm and 250 ohm respectively. What will be the back e.m.f. produced when it takes a load current of 21A. 220 V. 150 V. 280 V. 240 V. 220 V. 150 V. 280 V. 240 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an auto transformer, for what value of turn ratio, power transferred by inductively and conductively are same? 1 any of the above 0 0.5 1 any of the above 0 0.5 ANSWER DOWNLOAD EXAMIANS APP
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