DC Motors Carbon brushes are preferable to copper brushes because _____ They have longer life They have lower resistance They reduce sparking They reduce armature reaction They have longer life They have lower resistance They reduce sparking They reduce armature reaction ANSWER DOWNLOAD EXAMIANS APP
DC Motors A dc motor can be easily identified by Size of conductor Winding Yoke Commutator Size of conductor Winding Yoke Commutator ANSWER DOWNLOAD EXAMIANS APP
DC Motors Usually wide and sensitive speed control is desired in case of Steel rolling mills Elevators Colliery winders Centrifugal pumps Steel rolling mills Elevators Colliery winders Centrifugal pumps ANSWER DOWNLOAD EXAMIANS APP
DC Motors The back emf in a dc motor ______ Opposes the applied voltage Aids the applied voltage Aids the armature current None of the listed here Opposes the applied voltage Aids the applied voltage Aids the armature current None of the listed here ANSWER DOWNLOAD EXAMIANS APP
DC Motors In a dc machines the residual magnetism is of the order of 2 to 3 percent 10 to 15 percent 20 to 25 percent 50 to 75 percent 2 to 3 percent 10 to 15 percent 20 to 25 percent 50 to 75 percent ANSWER DOWNLOAD EXAMIANS APP
DC Motors The friction and windage losses in a dc motor depends upon Armature current Speed Flux Field and armature resistance Armature current Speed Flux Field and armature resistance ANSWER DOWNLOAD EXAMIANS APP
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