Computer Programming MCQs

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. Dummy coils
B. Commutator
C. Eye bolt
D. Equilizer rings

A. Using conductor of annealed copper
B. Using commutator with large number of segments
C. Using carbon brushes of superior quality
D. Using equiliser rings

A. High voltage, high current
B. Low voltage, high current
C. High voltage, low current
D. Low voltage, low current

A. 2 : 3
B. 3 : 1
C. 3 : 2
D. 1 : 3

A. Graphite brushes
B. Carbon brushes
C. Metal graphite brushes
D. None of the above

A. E/2
B. 2e
C. Slightly less than e
D. E

A. Silicon steel
B. Copper
C. Non-ferrous material
D. Cast-iron

A. Brushes should be of proper grade and size
B. Brushes should smoothly run in the holders
C. Smooth, concentric commutator properly undercut
D. All of the above

A. Identified by the scarring of the commutator segment to which open circuited coil is connected
B. Indicated by a spark completely around the commutator
C. Both a. and (b)
D. None of the above