Electrical Machines A 4 pole, 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 720 rpm, the supply frequency is 60 Hz 40 HZ 50 Hz 25 Hz 60 Hz 40 HZ 50 Hz 25 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The effect of ------------------ on main field flux is armature reaction? armature mmf armature current All of these armature flux armature mmf armature current All of these armature flux ANSWER DOWNLOAD EXAMIANS APP
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 Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to coil resistance. reactance voltage induced in the coil. None of these armature emf. coil resistance. reactance voltage induced in the coil. None of these armature emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In the V curve shown in figure below for a synchronous motor, the parameter of Y and X coordinates are, respectively Armature current and field current. Torque and field current. Power factor and field current. Armature current and torque. Armature current and field current. Torque and field current. Power factor and field current. Armature current and torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2 and 3 1 and 3 1, 3 and 5 1, 2, 3 and 5 1, 2 and 3 1 and 3 1, 3 and 5 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
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