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 Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 and 2 1 alone 2 and 3 1 and 3 1 and 2 1 alone 2 and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The introduction of interpoles in between the main poles improves the performance of a dc machine, because the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque a counter-emf is induced in the coil undergoing commutation the flux waveform is improved with reduction in harmonics the inequality of air-gap flux on the top and bottom halves of the armature is removed the interpoles produce additional flux to augment the developed torque a counter-emf is induced in the coil undergoing commutation 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 The interpoles in dc machines have a tapering shape in order to reduce the overall weight economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the saturation in the interpole reduce the overall weight economise on the material required for interpoles and their windings increase the acceleration of commutation reduce the saturation in the interpole ANSWER DOWNLOAD EXAMIANS APP
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