D.C. Generators

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. electromagnets
B. permanent magnets
C. both A. and B.
D. none of the above

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. Compensating winding in a D.C. machine helps in commutation
B. In a D. C. generator interpoles winding is connected in series with the armature winding
C. Back pitch and front pitch are both odd and approximately equal to the pole pitch
D. Equilizing bus bars are used with parallel running of D.C. shunt gen¬erators

A. just ahead of magnetic neutral axis
B. in magnetic neutral axis
C. just behind the magnetic neutral axis
D. none

A. lap winding
B. wave moving
C. duplex winding
D. any of the above