What is frequency?

  • (noun): The ratio of the number of observations in a statistical category to the total number of observations.
    Synonyms: relative frequency
    See also — Additional definitions below


Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its period (the interval between beats) is half a second.

Read more about Frequency.

Some articles on frequency:

Distress Radiobeacon - Frequency - Cospas-Sarsat Incompatible Beacon Frequencies
121.5 MHz VHF ± 6 kHz (frequency band protected to ±50 kHz) (Satellite detection ceased on 1 February 2009, but this frequency is still used for short-range location during a search and ...
Frequency Ranges
... The frequency range of a system is the range over which it is considered to provide a useful level of signal with acceptable distortion characteristics ... A listing of the upper and lower limits of frequency limits for a system is not useful without a criterion for what the range represents ... Allocation of radio frequency ranges to different uses is a major function of radio spectrum allocation ...
Power Inverter - Applications - Variable-frequency Drives
... A variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor ... In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from main AC power ... Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters ...
Index Of Electronics Articles - F
... synchronization – Framing bit – Freenet – Free-space loss – Freeze frame television – Frequency assignment – Frequency averaging – Frequency counter ...
Power Inverter - Applications - Induction Heating
... Inverters convert low frequency main AC power to higher frequency for use in induction heating ... The inverter then changes the DC power to high frequency AC power ...

More definitions of "frequency":

  • (noun): The number of occurrences within a given time period (usually 1 second).
    Example: "The frequency of modulation was 40 cycles per second"
    Synonyms: frequence, oftenness
  • (noun): The number of observations in a given statistical category.
    Synonyms: absolute frequency

Famous quotes containing the word frequency:

    The frequency of personal questions grows in direct proportion to your increasing girth. . . . No one would ask a man such a personally invasive question as “Is your wife having natural childbirth or is she planning to be knocked out?” But someone might ask that of you. No matter how much you wish for privacy, your pregnancy is a public event to which everyone feels invited.
    Jean Marzollo (20th century)

    One is apt to be discouraged by the frequency with which Mr. Hardy has persuaded himself that a macabre subject is a poem in itself; that, if there be enough of death and the tomb in one’s theme, it needs no translation into art, the bold statement of it being sufficient.
    Rebecca West (1892–1983)