Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to too rapid reversal of current. under commutation. over commutation. any of the above. too rapid reversal of current. under commutation. over commutation. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The starting resistance of DC motor is generally around 500 ohms. 1000 ohms. Low. Infinitely large. around 500 ohms. 1000 ohms. Low. Infinitely large. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor especially the cage rotors slots are nearly parallel to shaft axis. This is called slip. cogging. crawling. skewing. slip. cogging. crawling. skewing. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by cooling the armature. increasing the excitation. increasing the input to the prime mover. reducing the load voltage. cooling the armature. increasing the excitation. increasing the input to the prime mover. reducing the load voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V dc series generator is driven at its rated speed. The no-load voltage across its armature terminals would be somewhat more than 230 V somewhat less than 230 V 230 V 6 V somewhat more than 230 V somewhat less than 230 V 230 V 6 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1/2. Would be equal to If1. Cannot be predicted due to insufficient data. Woud be equal to 2If1. Would be equal to If1/2. Would be equal to If1. ANSWER DOWNLOAD EXAMIANS APP
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