What is the term for a vibration containing components at multiples of a base frequency?

• A. Damping
• B. Natural frequency
• C. Resonance
• D. Harmonics

Answer: (D)

Harmonics are the frequency components that are integer multiples of the fundamental (base) frequency. When a vibration contains components at 2x, 3x, 4x the base frequency, those features are harmonics of the fundamental. This describes the spectral content of a periodic signal and is what you’d see in Fourier analyses or in the timbre of a vibrating system.

Damping refers to energy loss and amplitude decay, not to the presence of multiple frequency components. Natural frequency is the system’s inherent free-vibration frequency, not a description of the spectrum. Resonance is the condition of a large response when forcing matches a natural frequency, not specifically about multiple frequency components.

So the term for a vibration containing components at multiples of a base frequency is harmonics.