Which term describes an exact submultiple of a fundamental frequency?

The correct term that describes an exact submultiple of a fundamental frequency is "Subharmonic." In the context of wave phenomena and acoustics, a fundamental frequency is the lowest frequency of a periodic waveform, and subharmonics are frequencies that are integer fractions of that fundamental frequency.

For instance, if the fundamental frequency is 100 Hz, then 50 Hz (which is half of 100 Hz) would be considered a subharmonic. This concept is critical in acoustic engineering and music, where understanding the relationships between different frequencies helps in sound design and analysis. Subharmonics have various applications, including in musical harmonies where they contribute to the richness of sound and in analyzing signals in electrical engineering.

The other terms listed have different meanings in relation to frequency. Harmonics refer to frequencies that are integer multiples of the fundamental frequency, while doubled frequency typically refers to a frequency that is twice the fundamental frequency. Carrier frequency is a term used primarily in telecommunications to describe a frequency that is modulated with an information signal. Understanding these distinctions helps clarify the concept of subharmonics in frequency analysis.