Question

the part that revolves in a motor or generator is called the a armature. b spindle. c buffer. d conductor.

Explanation:

In motors and generators, the rotating part is the armature. It is designed to carry current and interact with the magnetic - field to produce motion (in motors) or electricity (in generators). A spindle is a shaft that supports rotating parts but is not the main current - carrying rotating part. A buffer is used for data or signal management and has no relation here. A conductor is a material that can carry electric current but is not a specific rotating component in this context.

Answer:

A. armature