light intensity plancks constant equation

The restriction of any property to discrete values is called quantization.(b) Energy of each photon is directly proportional to frequency of radiation. Such packets are known as quantum or photon.

(a) The radiation energy emitted or observed in the form of small packets of energy(in discrete quantities and not in a continuous manner). Their frequency of oscillation is changed by interaction with oscilators of electromagnetic radiation Planck was able explain the phenomenon of black body radiation by assumption that absorption and emmission of radiation arises from oscillator Several attempts were made to predict the intensity of radiation as a function of wavelength, but Scientist was not able to explain all these with the theory of electromagnetic waves The amount of light emitted (intensity of radiation) from a black body and its spectral distribution depends only on its temperature.Īlso At a given temperature, intensity of radiation emitted increases with the increase of wavelength, reaches a maximum value at a given wavelength and then starts decreasing with further increase of wavelength, as shown in below figure.Īlso, as the temperature increases,maxima of the curve shifts to short wavelength.

It radiates same amount of energy per unit area as it absorbs from its surrounding in any given The exact frequency distribution of emitted radiations from black body depends only on its temperature.Īlso a black body is in thermal equilibrium with its surroundings. The ideal body which emit and absorbs all the frequencies is called Black body and the radiation emitted by such body is called Black body radiation. Also when the surface of an object is irradiated with light (electromagnetic radiation), a part of radiant energy is generally reflected as such, a part is absorbed and a part of it is transmitted. Hot objects emit electromagnetic radiations over a wide range of wavelengths.Intensities of radiations of different wavelengths emitted by hot body depend upon its Maxwell Theory of Electromagnetic waves or radiation was able to explain diffraction and interference but it was not able to explain the nature of emission of radiation from hot bodies (black -body radiation), ejection of electrons from metal surface when radiation strikes it (photoelectric effect), variation of heat capacity of solids as a function of temperature BLACK BODY RADIATIONS:.

Light intensity plancks constant equation