The SI unit of frequency indicating the number of cycles per second (symbol Hz). The name is in honour of Heinrich Hertz, an early German investigator of radio wave transmission.

Dimension: T-1

1 Hz = 1 s-1

infrasound<20 Hz
lower audible limit20 Hz
middle C264 Hz
treble A440 Hz
upper audible limit20000 Hz
VHF radio30 to 300 MHz
UHF radio300 to 3000 MHz
Red end of visible spectrum4.284x1014Hz
Violet end of visible spectrum7.495x1014Hz

Gigahertz (GHz)

A unit of frequency equal to 109 per second, or 1 per nanosecond. Cellular phones and microwave ovens operate with radio waves having frequencies in the gigahertz range.

See also: Frequency, Hertz Heinrich.

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Subjects: Audio Electronics Noise & Vibration Physics