Visible Light Waves

What is Light Waves?

● Light is a form of electromagnetic radiation. Human eye has the capability to detect or sense some part of the complete electromagnetic spectrum.

● The portion of the electromagnetic spectrum which is sensed by our human eye having wavelength in the range between 380nm and 750nm is called Visible light. Visible

● Light travels in straight line.

SPEED OF

LIGHT IN

VACUUM:-

3 × 1

08 m s–

1.

● Wavelength of visible is defned as the distance between the two consecutive crests or between two consecutive troughs.

● Wavelength of the Visible Light ranges from 380nm to 750 nm.

● In the electromagnetic spectrum, Infrared rays has higher wavelength than the visible rays and the ultraviolet rays has smaller wavelength as compared to the visible light.

● The visible light contains different types of colors when when the light is made to pass through the prism.

● Colors are produced based on their wavelength.

● Long Wavelength Visible Light is the Red visible light.

● The wavelength of the Red visible light ranges from the 625 nm to the 750 nm.

● The Smallest Wavelength Visible Light is the Violet visible light.

● The violet visible light has wavelength which ranges from 380 nm to 435 nm.

● Frequency of Visible Light is defined as the number of crests which passes through a particular point in a second.

● It is represented in hertz. ● Frequency of waves is inversely

proportional to their wavelength, which means that higher the wavelength, lower is the frequency and vice versa. The frequency range of the visible light is between 400 to 400 to 790 THz. 790 THz.

WAVELENGHT OF VISIBLE LIGHT

VISIBLE LIG HT SPECTRUM● Different types of radiations are present In the electromagnetic spectrum. ● Each type of rays has their spectrum or range of frequencies in the electromagnetic

spectrum. ● In other words we can say that in the complete electromagnetic spectrum, the

portion of the electromagnetic spectrum which can be detected by the human eye is termed as the visible light spectrum.

VISIBLE LIGHT SPECTRUM CHARTVIOLET● Wavelength 425 - 400 nm● Frequency 700 - 790 THz● Complementary color

yellow

INDIGO● Wavelength 420-425 nm● Frequency 670 - 700 THz● Complementary color

orange

BLUE● Wavelength 500 - 450 nm● Frequency 670 - 700 THz● Complementary color

Red

GREEN

● Wavelength 570 - 500 nm

● Frequency 580 - 530 THz

● Complementary colour red

YELLOW● Wavelength 590 - 570

nm

● Frequency 530 - 510 THz

● Complementary color - Violet

ORANGE

● Wavelength 610 - 590 nm● Frequency 510 - 480 THz● Complementary color Indigo

RED● Wavelength 750 - 610 nm● Frequency 480 - 405

THz● Complementary color

Blue

VISIBLE LIGHT ENERGY

● According to the particle theory of light, light consists of particles called as photons.

● Energy of the visible light is given by the formulae: E=hf

Where,

E = Energy of the light wave

h = Planck’s constant

f = frequency of the wave

VISIBLE LIGHT TRANSMITTANCEVISIBLE LIGHT TRANSMITTANCE

● When visible light falls on a substance, some of the light energy gets refracted, some gets refracted, and some gets absorbed by the substance.

● Visible light transmittance is defined as the fraction of incident light on the substance which passes through the substance at a particular frequency or wavelength.

● Visible light transmittance is defined as the ratio of the intensity of the Incident light on the substance to the intensity of light which passes through the substance or comes out from the substance.

● Visible Light Communication: Visible Light Communication: Visible light is also used for the communication purposes. Visible light communication is a type of data communication in which visible light is used as a medium to transfer the data. Led and lamps are also used for VLC.

VISIBLE LIGHT WAVES

● Light shows both types of properties, particle and wave nature.

● As a wave, visible light shows most of the properties which are shown by waves like reflection, refraction, diffraction, absorption .

● Visible light always travels in the form of straight line.

● Most important Visible Light Uses is that it makes us to see the different objects or substances.

● It helps in our day today life. It helps in driving ● etc. Used by the green plants for photosynthesis. Then it is also used for photoelectric effect to produce current or electricity.

VISIBLE LIGHT FACTS

● Wavelength: 380 to 750nm.

● It travels in straight line.

● Speed of light in vacuum is approx 3 × 108 m s–1

● Light shows both types of nature, particle as well as wave.

● Light shows the properties like refection refraction, absorption, diffraction etc.

DIPERSION● Dispersion means spreading or distributing of the particles over a wide

area. Here in physics we use this term when the light falls on any surface.

● The splitting up of white light into seven colors on passing through a splitting up of white light into seven colors on passing through a transparent medium like a glass prism is called as ‘Dispersion of white transparent medium like a glass prism is called as ‘Dispersion of white light’.light’.

..THE END..