What is the role of the commutator in a generator?

The role of the commutator in a generator is to change alternating current (AC) produced in the armature into direct current (DC) before it is delivered to the external circuit. In generators, especially those designed to produce DC, the armature rotates within a magnetic field, inducing an electromotive force (EMF) according to Faraday's law of electromagnetic induction. This process creates alternating current due to the continually changing direction of the induced EMF as the armature rotates.

The commutator is a key component that ensures that the output current flows in a single direction, thus transforming the alternating current generated in the armature into a unidirectional flow of direct current. It does this by periodically reversing the connection of the armature windings to the external circuit at appropriate intervals during each rotation. This switching action allows for a more stable and usable DC output from the generator, which is essential for many applications that require direct current.

While the other options might connect to generator functions in various ways, they don't specifically address the primary function of the commutator in the context of converting AC to DC. The commutator's ability to ensure a consistent DC output is crucial for the efficiency and functionality of DC generators.