A. lie under south pole
B. lie under north pole
C. lie under interpolar region
D. are farthest from the poles
Related Mcqs:
- The material for commutator brushes is generally_______________?
A. mica
B. copper
C. cast iron
D. carbon - The number of brushes in a commutator depends on______________?
A. speed of armature
B. type of winding
C. voltage
D. amount of current to be collected - If brushes of a D.C. generator are moved in order to bring these brushes in magnetic neutral axis, there will be________________?
A. demagnetisation only
B. cross magnetisation as well as mag¬netisation
C. crossmagnetisation as well as demagnetising
D. cross magnetisation only - The commutator segments are connected to the armature conductors by means of___________?
A. copper lugs
B. resistance wires
C. insulation pads
D. brazing - Two generators are running in parallel. One of the generators may run as motor for which of the following reasons ?
A. The direction of that generator is reversed
B. The speed of that generator is increased
C. The field of that generator is weakened
D. That generator takes large share of loads - The insulating material used between the commutator segments is normally_____________?
A. graphite
B. paper
C. mica
D. insulating varnish - In case of D.C. machine winding, number of commutator segments is equal to______________?
A. number of armature coils
B. number of armature coil sides
C. number of armature conductors
D. number of armature turns - To avoid formation of grooves in the commutator of a D.C. machine?
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 - For both lap and wave windings, there are as many commutator bars as the number of_____________?
A. slots
B. armature conductors
C. winding elements
D. poles - Copper brushes in D.C. machine are used_____________?
A. where low voltage and high currents are involved
B. where high voltage and small cur-rents are involved
C. in both of the above cases
D. in none of the above cases
