05-01-2018, 04:32 PM
Reflection
* Reflection is a phenomenon of bouncing back of light when a beam of light falls on a surface.
* Refraction is the bending of light when a ray of light travels from one medium to another.
*Due to change of medium, the phase velocity of the wave is changed but its frequency remains constant
*When a scale is immersed in a glass of water, it seems to be bended due to - refraction.
*Star appears to be twinkling due to -Refraction
*Optical illusion which is observed usually in deserts and highways on hot summerdays -Mirage
*The phenomenon of mirage in deserts is due to - Refraction
*Fata Morgana is a term associated with -Mirage
*Snell’s law is related with Refraction.
*The tank appears shallow than its actual depth due to- Refraction
*Device which works by the principle of reflection and refraction
Ans : Periscope
*The measure of optical density of the medium is Refractive index Refractive index of a medium
= Speedof light in vacuum/ Speed of light in medium
Refractive Index
*Vacuum - 1
*Ice - 1.31
*Water - 1.33
*Diamond - 2.42
Total Internal Reflection
*The total internal reflection principle finds its ( application in the construction of optical fibres, endoscopy, vehicle reflectors, binoculars etc.
*A diamond sparkles due to total internal reflection because it has a high refractive index.
*Working principle of Optical fibre
Ans : Total Internal reflection
*Indian physicist who invented optical fibre
Ans : Narinder Singh Kapany
*Working principle of automotive rain sensors
Ans : Total Internal Reflection
*Optical fibres are light pipes which carries optical energy from one part to another without any loss in energy.
Dispersion
*The splitting of composite, beam of light into its constituent colours is called
Ans : dispersion of light.
*It was discovered by
Ans : Sir Isaac Newton.
*Device used for the splitting of composite beam of white light into its constituent colours
Ans : Prism
*Rainbow is caused by Total Internal reflection, refraction and dispersion of light by the water particles present in the atmosphere.
