Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3600 rpm. 3000 rpm. 600 rpm. 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. 500 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Field weakening control method is used for the _________ ? both A and B None of these below rated speed above rated speed both A and B None of these below rated speed above rated speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors are preferred in lifts? DC series motors. DC shunt motors. DC compound motors. None of these DC series motors. DC shunt motors. DC compound motors. None of these 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, 2, 3, 4 2, 3, 4 1, 3, 5 1, 2, 5 1, 2, 3, 4 2, 3, 4 1, 3, 5 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, 3 and 5 1, 2, 3 and 5 1 and 3 1, 2 and 3 1, 3 and 5 1, 2, 3 and 5 1 and 3 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous generator, inverted V curve is drawn between field current on Y-axis and power factor on X-axis field current on X-axis and armature current on Y-axis field current on X-axis and power factor on Y-axis field current on Y-axis and armature current on X-axis field current on Y-axis and power factor on X-axis field current on X-axis and armature current on Y-axis field current on X-axis and power factor on Y-axis field current on Y-axis and armature current on X-axis ANSWER DOWNLOAD EXAMIANS APP