Wavelength of Visible Light and Its Calculation

The scientist ‘Sir Isaac Newton’ is a mathematician, theologian, author, physicist, and astronomer. He is broadly recognized as one of the most significant scientists for all time. He is the main figure in the revolution of science. He was the first person to check the visible light from the sun that transmits through a prism & generates a light beam. This beam can be separated into numerous colors like VIBGYOR (violet, indigo, blue, green, yellow, orange, and red. The ‘RogerBacon is an English philosopher the first person who marked that spectrum exhibits in a glass of water. When electromagnetic radiation occurs within a particular section of the electromagnetic spectrum is known as light. Generally, the term light refers to visible light and it is visible to the human eye. Experimentally, the light speed is found in vacuum to be 299,792, 458 m/sec or 3X108 m/sec. This article gives an overview of the wavelength of visible light and its working

What is the Wavelength of Visible Light?

When electromagnetic radiation occurs within a particular section of the electromagnetic spectrum is known as light. Generally, the term light refers to visible light and it is visible to the human eye. Experimentally, the light speed is found in vacuum to be 299,792, 458 m/sec or 3X108 m/sec. Sometimes in physics, any wavelength’s electromagnetic radiation refers to the term light. There are different kinds of radiations available like radio, gamma, microwaves, and x-rays. All these are forms of light and the study of this is called optics. We know that light doesn’t travel in a straight line but travels in the form of a transverse wave. These waves include consecutive troughs and crests. A wavelength can be defined as the distance between two crests and troughs. The units of wavelength are micrometers or nanometers. The symbol of wavelength is ‘λ’.

wavelength
wavelength

The categorization of electromagnetic waves can be done based on the frequency otherwise wavelength. The wavelength range of visible light ranges from 400 nanometers to 700 nanometers. In a complete electromagnetic spectrum, the light makes up only a small portion. The waves like electromagnetic with high frequencies & shorter wavelengths include different rays like UV, gamma and X-rays. Similarly, electromagnetic waves using fewer frequencies and long wavelengths include microwaves, IR, TV and radio waves.

  • For gamma rays, the frequency range is 1020 to 1024 and the wavelength range is 10-12 m
  • For x-rays, the frequency range is 1017 to 1020 and the wavelength range is 1 nm to 1 pm
  • For UV–rays, the frequency range is 1015 to 1017 and the wavelength range is 400 nm to 1 nm.
  • For visible rays, the frequency range is 4 to 7.5X1014 and wavelength range is less than 750 nm – 400 n
  • For near IR rays, the frequency range is 1*1014 – 4*1014and wavelength range is less than 2.5 μm – 750 nm
  • For IR rays, the frequency range is 1013 to 1014 and the wavelength range is 2.5 μm to 2.5 μm
  • For microwaves rays, the frequency range is 3*1011 – 1013 and wavelength range is less than 1mm to 25 μm
  • For radio rays, the frequency range is < 3*1011 and wavelength range is less than > 1 mm

What is Visible Spectrum?

The visible spectrum is a visible area of the electromagnetic wave and it is noticeable to the eyes of a human. The range of visible spectrum in the electromagnetic spectrum ranges from the region of IR to the ultraviolet. The detection range of the light spectrum can range from 400 nm to 700 nm. Once this range is crossed, then the human eye cannot observe the electromagnetic waves. But these waves can be observed like the rainbow colors wherever each color contains a different wavelength.

electromagnetic-spectrum
electromagnetic-spectrum
  • For the red color, the wavelength range is from 750 to 610 nm and frequency ranges from 480 to 405 THz.
  • For orange color, the wavelength range is from 610 to 590 nm and frequency ranges from 510 to 480 THz.
  • For yellow color, the wavelength range is from 590 to 570 nm and frequency ranges from 530 to 510 THz.
  • For green color, the wavelength range is from 570 to 500 nm and frequency ranges from 580 to 530 THz.
  • For blue color, the wavelength range is from 500 to 450 nm and frequency ranges from 670 to 600 THz.
  • For indigo color, the wavelength range is from 450 to 425 nm and frequency ranges from 600 to 700 THz.
  • For violet color, the wavelength range is from 425 to 400 nm and frequency ranges from 700 to 790 THz.

How is the Wavelength of Light Calculated?

When the light has the properties like a particle and a wave then it can be expressed in two equations.

V = λ*f
E = h*f

Where,

The velocity of light is ‘V’, the wavelength of light is ‘λ’, the frequency of the light is ‘f’, the energy of the light wave is ‘E’ and Planck’s constant is ‘h’

The value of Planck’s constant is 6.64×10−34 j/sec.

Here, the above equation specifies the nature of wave light.

Here, the first equation in the above denotes the wave nature of the light whereas the second equation in the above specifies the exact nature of the light.

Example Problem

The wavelength of visible light can be calculated like the following. The frequency value is f = 6.24×1014Hz.

We know the values of frequency f = 6.24×1014Hz.

Light velocity v = 3×108m/sec

According to the light wavelength formula λ= ν*f

λ = (3×10^8 / 1)* 06.24×1014

λ = 4.80 x 10−7

Thus, this is all about the wavelength of visible light. From the above information, finally, we can conclude that these light waves are electromagnetic waves that are visible. The wavelength of these light waves ranges from 400nm to 720 nm and it is denoted with ‘λ’, whereas the frequency of these light waves ranges from 400 THz to 789 THz. Here the value of 1 THz is equal to 1012Hz. The applications of visible light mainly include satellite, spectrophotometer, and rainbow.

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