USCG Exam PracticeElectrical fundamentals — DC/AC, motors, distribution
In a DC generator, what is the purpose of the commutator?
- A. To regulate field current and control output voltage.
- B. To increase the number of armature coils and smooth the output.
- ✓ To reverse the external circuit connections at the instant the induced voltage would reverse, producing unidirectional output.Correct
- D. To convert mechanical energy into magnetic flux in the field windings.
Why C is correct
The commutator is a split ring whose segments, contacted by carbon brushes, reverse the external connections to the loop at the instant the induced voltage would reverse, so the brushes always deliver current in one direction. NEETS Mod. 5 §1-1.
Cited:NEETS Mod. 5 §1-1