Introduction
In physics, wavelength is the distance between repeating units of a propagating wave of a given frequency. It is commonly designated by the Greek letter lambda (λ). Examples of wave-like phenonomena are light, water waves, and sound waves.
In a wave, a property varies with the position. For example, this property can be the air pressure for a sound wave, or the magnitude of the electric or the magnetic field for light. The wavelengths of frequencies audible to the human ear (20 Hz – 20 kHz) are between approximately 17 mm and 17 m. Visible light ranges from deep red, roughly 700 nm to violet, roughly 400 nm (430--750 THz). For other examples, see electromagnetic spectrum.
> Wave forms
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