Correct option is B
The
commutator in a DC generator acts as a
rectifier.
Its primary function is to convert the alternating current (AC) generated in the armature windings into direct current (DC) by reversing the direction of current in the external circuit every half cycle.
Armature:
The rotating part of the DC machine is called the armature. The armature consists of a shaft upon which a laminated cylinder, called armature core, is mounted. The armature core has grooves or slots on its outer surface. The laminations are insulated from each other and tightly clamped together. In small machines the laminations are keyed directly to the shaft. In large machines they are mounted on a spider. The purpose of using laminations is to reduce eddy-current loss.
The insulated conductors are put in the slots of the armature core. The conductors are wedged and bands of steel wire are fastened round the core to prevent them flying under centrifugal forces. The conductors are suitably connected. This connected arrangement of conductors is called armature winding. Two types of windings are used-wave and lap.
