Frequency And Wavelength:
The EM waves travel via space at the speed of light that is around 2.99792 x 108 m/s (1.86262 x 105 mi/s). This is frequently rounded up to 3.00 x 108 m/s, stated to three considerable figures. The wavelength of an EM field in free space acquires shorter as the frequency becomes higher. At 1 kHz, the wavelength is around 300 km. At 1 MHz, the wavelength is around 300 m. At 1 GHz, the wavelength is around 300 mm. At 1 THz, an EM signal has a wavelength of around 0.3 mm-too small that you would require a magnifying glass to see it.
The frequency of an EM wave can obtain much higher than 1 THz; several of the most energetic recognized rays have wavelengths of 0.00001 Angstrom (10-5 Å). The Angstrom is equal to 10-10 m and is used by few scientists to represent very short EM wavelengths. The microscope of great magnifying power would be required to see an object with a length of 1 Å. The other unit, increasingly prefer by scientists nowadays, is the nanometer (nm), here 1 nm = 10-9 m = 10 Å.
The formula for wavelength λ in meters, as a function of the frequency f in hertz, and for an EM field in open space is as follows:
λ = 2.99792 x 108 /f
This similar formula can be used for λ in millimeters and f in kilohertz, for λ in micrometers, f in megahertz, for λ in nanometers and f in gigahertz. Keep in mind your prefix multipliers: 1 millimeter (1 mm) is 10-3 m, 1 micrometer (1 µm) is 10-6 m, and 1 nanometer (1 nm) is 10-9 m.
The formula for frequency f, in hertz, as a function of wavelength λ, in meters, for an EM field in open space is known by transposing f and λ in the previous formula:
f = 2.99792 x 108/λ
Since in the previous situation, this formula will work for f in kilohertz and λ in millimeters, for f in megahertz and λ in micrometers, and for f in gigahertz and λ in nanometers.