💡 Properties of Light 💡
Rectilinear Propagation of Light
Reflection of Light
Refraction of Light
Total Internal Reflection
Scattering of Light
Dispersion of light
Interference & Diffraction of Light
Polarisation.
💥💥Rectilinear Propagation of Light💥💥
👉Light travels in a straight line. When an Opaque object is placed between a source of light and a screen .If light comes from a point source then the shadow obtained is a region of Total Darkness, Called "Umbra" , If Light comes from an extended source then in the shadow obtained, the Umbra is surrounded by a region of partial darkness, called "Penumbra"
👉When the Moon comes between The Sun and the Earth, then the shadow of the moon falls on the Earth and the Sun is not Visible at Earth. This phenomena is called "Solar Eclipse"
👉When the Earth comes between the Sun and the Moon, then the shadow of the Earth falls on moon and the Sunlight do not incident on the Moon. Therefore, moon is not visible at the Earth. This phenomena is called "Lunar Eclipse"
💥Reflection of Light💥
👉The phenomena of renouncing back of light into the same medium when it strikes on a smooth shining surface such as a plane mirror, is called reflection of light.
👉LAWS OF REFLECTION
- The angle of incidence is always equal to the angle of reflection
- The incident ray, the reflected ray and the normal at the point of incidence all in the same plane.
💥💥Refraction of Light💥💥
👉The phenomena of deviation of light rays from its path from its path when it travels from one transparent medium to another transparent medium, is called Refraction of Light.
👉Bending of a linear object when it is partially dipped in a liquid inclined to the surface of the liquid
👉A coin appears at lesser depth in water.
👉Oval shape of sun in the morning and evening
👉When light rays travel from a denser medium towards a rarer medium it deviates away from the normal. Therefore, a pond appears shallower
👉Twinkling of Stars is due to Atmospheric refraction
💥💥Total Internal Reflection of Light 💥💥
- When a light ray travelling from a danser medium towards a rarer medium is incident at the interface at an angle of incidence greater than critical angle ,then light rays reflected back into the denser medium. This phenomenon is called Total Internal reflection
👉Sparkling of Diamond
👉Formation of Mirage in deserts
👉Shining of air bubble in water
💥💥Scattering of Light💥💥
👉"The sky appears blue" because in sunlight, the blue colour of light is scattered maximum and this scattered blue light enters our eyes and therefore Sky appears blue
👉"The sun appears Red" during sunshine and sunset
👉"Clouds appears White" because clouds are consists of large size pf droplets water and dust particles which scatter all colours of light equally. The mixture of all seven colours of sunlight is white.
👉"Sky appears Black" to astronauts from Space because there is no atmosphere in space and therefore no scattering of light takes place.
👉"Danger Singnals" are of red colours because red colour of light scatters least and therefore these signals can be seen from far away.
💥💥Dispersion of Light💥💥
👉when white light is incident on a glass prism, it splits into 7 colours components in the sequence of "VIBGYOR" this phenomena is called Dispersion of light .
👉Formation of Rainbow is natural example of the dispersion of light. Here water molecules act as prisms.
💥💥Interference & Diffraction of light (wave)💥💥
👉The phenomena of redistribution of energy due to superposition of waves is called interference of light waves. The interference taking place at points of maximum intensity is called Constrictive interference. The interference taking place at points of minimum intensity is called Destructive interference
👉The bending of light wave around the corners of an obstacle or aperture is called Diffraction of light
💥💥Polarisation of Light💥💥
👉The phenomena of restricting of electric vectors of light into a single direction is called Polarisation.
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