The electromagnetic spectrum is the distribution of electromagnetic radiation according to energy (or equivalently, by virtue of the relations in the previous section, according to frequency or wavelength). Show
Regions of the Electromagnetic SpectrumThe following table gives approximate wavelengths, frequencies, and energies for selected regions of the electromagnetic spectrum.
The notation "eV" stands for electron-volts, a common unit of energy measure in atomic physics. A graphical representation of the electromagnetic spectrum is shown in the figure below.
Thus we see that visible light and gamma rays and microwaves are really the same things. They are all electromagnetic radiation; they just differ in their wavelengths. The Spectrum of Visible LightIn the same way that we sense frequency of sound as pitch, we sense the frequency of light as color. Notice how small the visible spectrum is over the full range of the electromagnetic spectrum. The visible part of the spectrum may be subdivided according to color, with red at the long wavelength end and violet at the short wavelength end, as illustrated (schematically) in the following figure.
How Roy G. Bv Lost a VowelThe sequence of colors red, orange, yellow, green, blue, and violet may be remembered by memorizing the name of that fine fellow "ROY G. BV". This was originally "ROY G. BIV", because it used to be common to call the region between blue and violet "indigo". In modern usage, indigo is not usually distinguished as a separate color in the visible spectrum; thus Roy no longer has any vowels in his last name.Infrared RadiationBeyond the red end of the visible spectrum is infrared radiation. This ranges from 700nm down to 0.1cm. We feel such radiation from a heat lamp but we cannot see this radiation. Radio WavesWe are familiar with radio waves from UHF, VHF, FM and AM transmissions. They have very long wavelengths. AM radio waves have the longest wavelengths in this group, and thus the smallest frequencies. UV, X-ray, Gamma-RaysThese shorter wavelength, higher energy rays are largely blocked out by the Earth's atmosphere. (We will later see more about why particular wavelengths are blocked compared to others. (see next slide). Thus Superman's "X-ray vision" is basically useless on Earth. Electromagnetism Light is part of a spectrum of electromagnetic energy that includes radio waves, microwaves, infrared radiation, visible light, ultraviolet "light", x rays, and gamma rays. Electromagnetic energy travels as waves that vary in wavelength. Radio waves and microwaves lie at the longer end of the spectrum of electromagnetic energy (kilometers and meters to centimeters and milimeters), while x rays and gamma rays have very short wavelengths (billionths or trillionths of a meter). Infrared radiation, what we experience as heat when we hold our hand near a warm object, is somewhat longer wavelengths than visible light. Visible light is simply electromagnetic radiation in a range of wavelengths that our eyes are sensitive to. Visible wavelengths range from 0.0007 milimeters for red light, through orange, yellow, green, and blue, to 0.0004 milimeters for violet light. Ultraviolet is shorter wavelengths than violet.  Where are radio waves on the electromagnetic spectrum?Most of the radio part of the EM spectrum falls in the range from about 1 cm to 1 km, which is 30 gigahertz (GHz) to 300 kilohertz (kHz) in frequencies. The radio is a very broad part of the EM spectrum. Infrared and optical astronomers generally use wavelength.
Which part of electromagnetic spectrum is closest to long range wavelength?Electromagnetic waves with longer wavelengths and lower frequencies include infrared light, microwaves, and radio and television waves.
What type of electromagnetic wave is radio?Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below.
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Which part of the electromagnetic spectrum is nearest to radio waves
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