Frekvenci

Frekvenci is a measure of how often a repeating event occurs in a given amount of time. In physics and engineering, frequency describes how many cycles of a periodic process happen each second and is measured in hertz (Hz). One hertz equals one cycle per second, and the relationship with the period T (the time for one cycle) is f = 1/T. For processes that are not strictly linear or sinusoidal, frequency still describes the rate of repetition but may be defined for different components or harmonics.

When the repeating signal is sinusoidal, angular frequency ω is used, defined as ω = 2πf, and it relates to the rate of rotation or oscillation in radians per second. Frequencies are found in many contexts: sound waves, electromagnetic waves, and rotating machinery. In sound, frequency largely determines pitch; in visible light, frequency (or wavelength) determines color. Spatial frequency describes how often a pattern repeats per unit distance, such as stripes on a material.

In signal processing and electronics, frequency is determined using instruments like frequency counters, oscilloscopes, or spectrum analyzers. The period, phase, and amplitude are related but distinct aspects of a signal. In digital systems, the sampling rate imposes a Nyquist frequency, half the sampling rate, to avoid aliasing—the misrepresentation of higher frequencies as lower ones.

Statistically, frequency can also refer to the number of occurrences of a value in a data set, with relative frequency expressed as the proportion of the total. Frequency analysis, via Fourier transforms, decomposes a signal into its frequency components and is fundamental in understanding spectra and noise.