Physics 4

പ്രകാശത്തിൻറെ പ്രത്യേകതകളായ റിഫ്‌ളക്‌ഷൻ, റിഫ്രാക്‌ഷൻ, ടോട്ടൽ ഇൻറെർണൽ റിഫ്‌ളക്‌ഷൻ, ഡിസ്പേഴ്‌സൺ, ഇന്റർഫെറൻസ്, ഡിഫ്രാക്ഷൻ, സ്‌കാറ്ററിങ്, പോളറൈസേഷൻ, ഡോപ്ലർ എഫക്ട് എന്നീ സുപ്രധാന ഭാഗങ്ങളാണ് ഇന്നത്തെ പാഠത്തിൽ ഉൾക്കൊള്ളിച്ചിരിക്കുന്നത് 

• Color having minimum wavelength

                 Violet

• Color having maximum wavelength

                 Red

• Color having minimum frequency

                 Red

• Color having maximum frequency

                 Violet

• Light that scatters most

                 Violet

• Light that scatters least

                 Red

• Color which reflects all other colors

                 White

• Color which absorbs all other colors

                 Black

• Color which absorbs maximum heat

                 Black

• Color which absorbs minimum heat

                 White

• Color which appears on the upper portion of the rainbow

                 Red

• Color which appears on the center of the rainbow

                 Green

• Color which appears on the lower portion of the rainbow

                 Violet

• Distance traveled by light in one year

                 Light year

• Unit used to measure distance between stars

                 Light year

• One light year is

                 9.46x1012

• One Parsec is

                 3.26 light years

• Quantum theory was put forward by

                 Max Plank

• According to Quantum theory, energy packets in light rays called

                 Quantum

• Quantum of light is known as 

                 Photon

• Phenomenon of emission of light from substances after absorption of Photons called as

                 Photo Luminescence

• Phenomenon of bouncing back of light when a beam of light falls on a surface

                 Reflection

• Bending of light when a ray of light travels from one medium to another

                 Refraction

• Phenomena of Mirage in deserts, Twinkling of stars, bending scale immersed in water\glass etc are due to

                 Refraction

• Reason for refraction of light when travels from one medium to another

                 Phase velocity of wave is changed but its frequency remain constant

• Snell's law is related with

                 Refraction

• Fata Morgana is a term associated with

                 Mirage (Superior form of Mirage)

• Measure of optical density of a medium is

                 Refractive index [Speed of light in vacuum/Speed of light in medium]

• Refractive index of Vacuum

                 1 [Ice : 1.31, Water : 1.33]

• Refractive index of Diamond

                 2.42

• Working principle of Optical fiber, endoscopy, Vehicle reflectors, Binoculars

                 Total Internal Reflection

• Sparkling of Diamond is due to

                 Total internal reflection in high refractive index

• Splitting of composite beam of light into its constituent colors is called

                 Dispersion of light

• Dispersion of light is discovered by

                 Issac Newton

• Device used to split composite light into constituent colors

                 Prism

• Rainbow is caused by

                 Total internal reflection, refraction and dispersion of light by water particles

• Red color in rainbow is seen at an angle of

                 42.8 Degree

• Violet color in rainbow is seen at an angle of

                 40.8 Degree

• Shape of rainbow while seeing from space

                 Circle

• Distribution of light when two or more high waves superimpose each other is called

                 Interference

• Colors in soap bubbles, oil layers etc are due to

                 Interference

• Interference was first observed by

                 Thomas Young

• Working principle of Holography\Hologram

                 Interference

• Process of spreading out of light into geometrical shadow of obstacle is called as 

                 Diffraction

• Projector in film theaters works on the principle of 

                 Diffraction

• Rings around the sun, Fringe pattern of CD etc are due to

                 Diffraction

• Blue color of Sky, Reddening of Sun at sunrise and sunset are due to

                 Scattering of light

• The light color which scatters most

                 Violet (Having shorter wave length)

• The light color which scatters least

                 Red (Having longer wave length)

• Black color of sky in Moon is due to 

                 Absence of scattering of light as there is no atmosphere

• Phenomenon of confining the vibration of a transverse wave to a particular direction is called

                 Polarization

• Brewster's Law is associated with

                 Polarization of Light

• Example of natural polarizing material

                 Tourmaline

• Polaroids are using in 

                 Aeroplane and car windows, sun glasses, Three dimensional pictures

• Light scattering by the particles in a colloid is known as

                 Tyndal effect

• Example of Tyndal effect

                 Sunlight passing through mist, blue color seen in smoke emitted from motor cycles

• Change in frequency of a light or sound wave when source or observer moves with respect to the other is known as

                 Doppler effect

• Increase in frequency (decrease in wave length) of visible light when it moves towards observer is called

                 Blue Shift

• Decrease in frequency (Increase in wave length) of visible light when it moves towards observer is called

                 Red Shift

• Blue shift, Red Shift, High pitch of siren of approaching ambulance is due to

                 Doppler effect
                                                                                                  (To be Continued...)