##  [Planck's Law](/plancks-law) 

  ##  [Planck's Law](https://engineering.quantumdictionary.io/plancks-law-0) 

  

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**Engineering & Applied Technologies Dictionary**

 







 

 

 

 



 

 

 

 

Definition

Planck's law gives the spectral radiance emitted by a blackbody in thermal equilibrium as a function of wavelength (or frequency) and absolute temperature, quantitatively expressed by B_λ(T) = (2hc^2/λ^5)·[1/(exp(hc/(λkT)) − 1)] (or its frequency-domain analogue), describing how emitted intensity varies across the spectrum.