Search results
Results From The WOW.Com Content Network
The electromagnetic spectrum is the full range of electromagnetic radiation, organized by frequency or wavelength. The spectrum is divided into separate bands, with different names for the electromagnetic waves within each band. From low to high frequency these are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and ...
In general, the relationship between wavelength, frequency, and the phase velocity of a sinusoidal wave is: v p = λ ν {\displaystyle v_{\text{p}}=\lambda \nu } Using the wavenumber ( k = 2 π / λ {\displaystyle k=2\pi /\lambda } ) and angular frequency ( ω = 2 π ν {\displaystyle \omega =2\pi \nu } ) notation, the previous equation can be ...
For example, a wavenumber in inverse centimeters can be converted to a frequency expressed in the unit gigahertz by multiplying by 29.979 2458 cm/ns (the speed of light, in centimeters per nanosecond); [5] conversely, an electromagnetic wave at 29.9792458 GHz has a wavelength of 1 cm in free space.
Defining equation SI units Dimension AM index: h, h AM = / A = carrier amplitude A m = peak amplitude of a component in the modulating signal . dimensionless dimensionless FM index: h FM = / Δf = max. deviation of the instantaneous frequency from the carrier frequency
Frequency is inversely proportional to wavelength, according to the equation: [26] = where v is the speed of the wave (c in a vacuum or less in other media), f is the frequency and λ is the wavelength. As waves cross boundaries between different media, their speeds change but their frequencies remain constant.
If the group velocity (see below) is wavelength-independent, this equation can be simplified as: [14] (,) = (+), showing that the envelope moves with the group velocity and retains its shape. Otherwise, in cases where the group velocity varies with wavelength, the pulse shape changes in a manner often described using an envelope equation .
For periodic waves in nondispersive media (that is, media in which the wave speed is independent of frequency), frequency has an inverse relationship to the wavelength, λ . Even in dispersive media, the frequency f of a sinusoidal wave is equal to the phase velocity v of the wave divided by the wavelength λ of the wave: f = v λ ...
[1] [2] Soon the term referred to a plot of light intensity or power as a function of frequency or wavelength, also known as a spectral density plot. Later it expanded to apply to other waves , such as sound waves and sea waves that could also be measured as a function of frequency (e.g., noise spectrum , sea wave spectrum ).