Light has dual nature. Light behaves as wave and particle.
Light travels fastest through vacuum.
Refractive index of a medium is defined as the ratio of speed of light in vacuum to the speed of light in the medium.
Translucent substances are those which allow a part of incident light to pass throgh them. Eg: Oiled paper.
The photoelectric effect refers to the emission, or ejection, of electrons from the surface of, generally, a metal in response to incident light.
Photoelectric effect was discovered by Heinrich Hertz. He proved that light is an electromagnetic wave.
Photoelectric effect was explained by Albert Einstein. He got the Nobel prize in 1921 for the scientific explanation ofPhotoelectric effect.
The velocity of light in different media are explained by Leon Foucalt.
Clark Maxwell discovered that visible light is a part of electromagnetic spectrum. He proposed the Electro magnetic theory of light.
The "Wave theory of light" was proposed by Christian Huygens.
The "Corpuscular theory" related to light was proposed by Sir Isaac Newton in 1675.
The "Quantum Theory" was proposed by Max Plank in 1900.
The bending of light when a ray of light travels from one medium to another is called Refraction.
The twinkling of stars is due to refraction of light. Also, a pond looks shallow due to refraction.
When a ray of light incident on a smooth surface and bounce back to the same medium, it is called Reflection.
When the ray of light is travelling from a denser to rarer medium and the angle of incidence is greater than the critical angle, then the light reflects back to the denser medium, obeying the laws of reflection. This phenomenon is called Total Internal reflection.
Optical fibre works based on Total Internal Reflection.
The diamond sparkles due to Total Internal Reflection.
A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. Mirage occurs as a result of refraction and Total Internal Reflection.
Interference is a phenomenon in which two waves superpose to form a resultant wave of greater, lower, or the same amplitude.
The colors that appears on the soap foam and on the oil spread water is due to Interference of light.
The splitting up of light ray into different colors is called Dispersion.
Diffraction is the spreading out of waves of light as it passes through a narrow aperture.
Blue color of sky is due to the scattering of light.
Rainbow is caused by dispersion, total internal reflection and refraction of light by the water particles present in the atmosphere.
A rainbow is always seen in the opposite direction of the sun.