A DC generator which is used to supply direct current in order to provide magnetizing current to an AC generator field is commonly known as what?

Correct Answer: Option A — exciter

An exciter is a dedicated direct-current generator mounted on the main shaft or driven separately to supply controllable magnetizing DC power to the rotating field poles of a synchronous AC generator, regulating terminal voltage in compliance with IEEE 45 and 46 CFR Subchapter J.