Dispersion: Dispersion, in wave motion, any phenomenon associated with the propagation of individual waves at speeds that depend on their wavelengths. Ocean waves, for example, move at speeds proportional to…
Month: November 2020
Bohr’s Quantization Rule
What is Bohr’s Quantization Rule? Bohr’s Quantization Rule: Of all possible circular orbits allowed by the classical theory, the electrons are permitted to circulate only in those orbits in which…
Einstein’s Coefficients
What are Einstein’s Coefficients? Einstein coefficients are mathematical quantities which are a measure of the probability of absorption or emission of light by an atom or molecule. The Einstein A…
Specific Rotation
What is Specific Rotation? Specific rotation, [α], is a fundamental property of chiral substances that is expressed as the angle to which the material causes polarized light to rotate at…
Concept Of Rest Mass of Photon
Concept Of Rest Mass of Photon Photons are said to be massless. The logic can be demonstrated as follows: Consider a “particle” accelerating to velocity v (a vector). As per…
Optical Activity
What is Optical Activity? Optical activity, the ability of a substance to rotate the plane of polarization of a beam of light that is passed through it. (In plane-polarized light,…
Fresnel’s theory
FRESNEL THEORY OF OPTICAL ACTIVITY The phenomenon of rotation of the plane of polarization of light traversing an isotropic optically active medium was first explained by Fresnel, near about 1820,…
Planck’s Law
What is Planck’s Law? Planck’s law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T, when there is no…