Dispersion: Dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency.
The component lights of different wavelengths travel with different speeds in same media. So the component lights of a single light like VIBGYOR of White light disperses if the single light of combination of other lights travel from one medium to the other.
Example: Rainbow is the natural phenomenon in which dispersion takes place. The cause of dispersion is that sun light consists of seven constituents (colours namely violet, indigo, blue, green, yellow, orange and red popularly referred to as VIBGYOR) that have different refractive index with respect to a medium. The wavelength of each colour is different that causes the difference in velocity of the corresponding light when passing from one medium to another.
Scattering of Light : Scattering of light is the deviation of light rays from its straight path. As light propagates through the atmosphere, it travels in a straight path until it is obstructed by bits of dust or gas molecules.
During sunrise and sunset, the sun is at the horizon and refractive index of the atmosphere of the earth decrease with height. Due to this, light reaching the earth's atmosphere from different parts of the vertical diameter of the sun enters at different heights in earth's atmosphere and so travels in media of different refractive indices at the same instant and hence, bend unequally. Due to this unequal bending of of light from the vertical diameter, the image of the sun gets destored and it apppears oval and larger. However, at noon when the sun is overhead, then due to normal incidence of light there is no bending of light and hence, the sun appears circular.
The sky appears blue because out of the seven colours of light, blue has the shortest wavelength, and therefore it experiences more scattering than other colours.
Scattering of light gives rise to many amazing and spectacular phenomena such as the Tyndall effect and the reddening of the sun at sunrise and sunset.
The Tyndall effect is the scattering of light by colloidal particles.
Yogita Ingle 6 years, 9 months ago
Dispersion: Dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency.
The component lights of different wavelengths travel with different speeds in same media. So the component lights of a single light like VIBGYOR of White light disperses if the single light of combination of other lights travel from one medium to the other.
Example: Rainbow is the natural phenomenon in which dispersion takes place. The cause of dispersion is that sun light consists of seven constituents (colours namely violet, indigo, blue, green, yellow, orange and red popularly referred to as VIBGYOR) that have different refractive index with respect to a medium. The wavelength of each colour is different that causes the difference in velocity of the corresponding light when passing from one medium to another.
Scattering of Light : Scattering of light is the deviation of light rays from its straight path. As light propagates through the atmosphere, it travels in a straight path until it is obstructed by bits of dust or gas molecules.
During sunrise and sunset, the sun is at the horizon and refractive index of the atmosphere of the earth decrease with height. Due to this, light reaching the earth's atmosphere from different parts of the vertical diameter of the sun enters at different heights in earth's atmosphere and so travels in media of different refractive indices at the same instant and hence, bend unequally. Due to this unequal bending of of light from the vertical diameter, the image of the sun gets destored and it apppears oval and larger. However, at noon when the sun is overhead, then due to normal incidence of light there is no bending of light and hence, the sun appears circular.
The sky appears blue because out of the seven colours of light, blue has the shortest wavelength, and therefore it experiences more scattering than other colours.
Scattering of light gives rise to many amazing and spectacular phenomena such as the Tyndall effect and the reddening of the sun at sunrise and sunset.
The Tyndall effect is the scattering of light by colloidal particles.
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