DC Motors
The friction and windage losses in a dc motor depends upon

Field and armature resistance
Flux
Armature current
Speed

ANSWER DOWNLOAD EXAMIANS APP

DC Motors
In variable speed motor

None of these
A weaker commutating field is needed at low speed than at high speed
Same commutating field is needed at low speed than at high speed
A stronger commutating field is needed at low speed than at high speed

ANSWER DOWNLOAD EXAMIANS APP