What term defines a frequency that is an integer multiple of a smaller basic frequency?

• A. Harmonic
• B. Period
• C. Wavelength
• D. Amplitude

Answer: (A)

When a frequency is an integer multiple of a smaller base frequency, that frequency is called a harmonic. The base frequency, or fundamental, sets the starting point, and the harmonics occur at integer multiples like 2x, 3x, and so on. This idea is central to how periodic signals are analyzed and synthesized; Fourier analysis shows any periodic waveform can be decomposed into harmonics at those integer-multiple frequencies. In music, what you hear as overtones are harmonics of the fundamental note. The other terms don’t describe this relationship: period is the time for one cycle (the reciprocal of frequency), wavelength is the spatial distance between peaks (dependent on propagation speed and frequency), and amplitude is the signal’s height, not the multiple relationship.