Wavelength of Light

Wavelength can be defined as the distance between two successive crests or troughs of a wave. It is measured in the direction of the wave.

Wavelength is the distance from one crest to another, or from one trough to another, of a wave (which may be an electromagnetic wave, a sound wave, or any other wave). Crest is the highest point of the wave whereas the trough is the lowest. Since wavelength is distance/length, it is measured in units of lengths such as metres, centimetres, milimetres, nanometres, etc

What is Visible Spectrum?

Visible spectrum is nothing but the observable region of the electromagnetic wave which is visible to human eyes. In the electromagnetic spectrum, the visible spectrum ranges from the infrared region to the UV region. We can detect the range of light spectrum from about 400 nanometers (violet) to about 700 nanometers (red) and after this range, the human eye is unable to see the rest of the electromagnetic waves.

We can see these waves as the colors of the rainbow where each color includes a different wavelength


Tables of Wavelength Of various color
Colour Wavelength Frequency
Violet 380-450 nm 668-789 THz
Blue 450-495 nm 606-668 THz
Green 495-570 nm 526-606 THz
Yellow 570-590 nm 508-526 THz
Orange 590-620 nm 484-508 THz
Red 620-750 nm 400-484 THz


White light: White light’s wavelength extends from 400 to 750 nm. When the white color is passed through the prism, the light spectrum is formed due refraction of different wavelengths through different angles
Ultraviolet Light: Ultraviolet light extends from the end of the visible region and the X-ray region in the electromagnetic spectrum, It gets its name as it is the light closest to the violet portion of the visible light and is in the range of 10 to 400 nm
Infrared Light: Infrared radiation has a longer wavelength than visible light and is close to the red portion of the visible spectrum of light. It extends from 750 nm t1 mm Infrared radiation cannot be seen but can be felt in the form of heat.
Red Light and Orange Light: Red light and orange lights whose wavelength lies between 620-750 nm and 590-620 nm respectively are best viewed naturally during sunrise and sunset. This is because the associated wavelengths of red and orange from sunlight are not properly scattered by the atmosphere during these times
Yellow Light: Yellow light has a wavelength between 570-590 nm Yellow light is emitted by low-pressure sodium lamps.
Green Light: Green color, whose wavelength extends from 495-570 nm, can be prominently seen in grass and leaves. Grass reflects green wavelength and absorbs all other wavelengths and thus appears green
Blue Light:  Blue light has a wavelength ranging from 500 to 450 nm. The atmosphere scatters shorter Wavelengths efficiently and thus the wavelength corresponding to the color blue is scattered efficiently by the atmosphere. That’s why the sky appears blue when we look up at it
Indigo Light Violet Light: With a wavelength between 450 and 425 nm indigo is a color which is between the primary color blue and the color violet in the color wheel. Violet with a wavelength of 425 to 400 nm is the visible light with the shortest wavelength. It has a shorter wavelength and is hence scattered more effectively by the atmosphere. But since our eyes are sensitive to blue color, the sky appears blue rather than indigo or violet color

I am scientist

I am scientist is a result of small effort to make huge impact on children. To stimulate the curiosity of young scientist towards science. Each idea will start with a experiment followed by reasoning the result , scientific learning, vocabulary (recap the big words used), useful reference website and books, along with free downloadable worksheets.

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