- (A) abrasion from dust
- (B) excessive spring pressure
- (C) rough commutator bars
- (D) high mica insulation between com-mutation bars
- (E) all of the above factors
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- (A) Dummy coils
- (B) Commutator
- (C) Eye bolt
- (D) Equilizer rings
- (A) mainly to reduce the eddy currents by providing local short-circuits
- (B) to provide path for the circulation of cooling air
- (C) to neutralise the cross-magnetising effect of the armature reaction
- (D) none of the above
- (A) Insulation failure between two commutator bars
- (B) Insulation failure between two turns of a coil
- (C) Two of more turns of the same coil getting grounded
- (D) All of the above
- (A) speed of armature
- (B) type of winding
- (C) voltage
- (D) amount of current to be collected
- (A) the brushes of opposite polarity should track each other
- (B) the brushes of same polarity should track each other
- (C) brush position has no effect on the commutator grooving
- (D) None
- (A) reduces generator e.m.f.
- (B) increases armature speed
- (C) reduces interpoles flux density
- (D) results in sparking trouble
- (A) cumulatively compounded long shunt
- (B) deferentially compounded long shunt
- (C) cumulatively compounded short shunt
- (D) differentially compounded short shunt
- (A) along neutral axis
- (B) along field axis
- (C) in any of the above positions
- (D) in none of the above positions
- (A) total copper loss and mechanical loss
- (B) armature copper loss and iron loss
- (C) shunt field copper loss and mechanical loss
- (D) iron loss and mechanical loss
