Question

Max plank equation and what each letter stand's for

Answer 1

Max Planck proposed that energy is transmitted in packets (quanta) of 
   E = h ν
           ν = nu  = frequency of the radiation or waves
           h = Planck's constant = 6.63 * 10⁻³⁴ J-sec

This is the minimum amount of energy that can be added-subtracted.  A (imaginary) particle that holds this energy is called as a photon.

There is also an equation/law for electromagnetic radiation from a black body that is called Plank's law.

  The spectral radiance emitted by a black body is the amount of energy and power it sends it off in the form of radiation in multiple frequencies.     B is expressed in terms of the power emitted by unit area of the body surface, captured in a unit solid angle area,  and per unit frequency range.

$B_\nu(\nu,\ T)=\frac{2h \nu^3}{c^2}*\frac{1}{e^{(\frac{h\nu}{k_B T})}\ -\ 1}\\\\ Spectral\ radiance\ per\ unit\ wavelength\ then\ is\\\\B_\lambda(\lambda,\ T)=\frac{2h c^2}{\lambda^5}*\frac{1}{e^{(\frac{h\ c}{\lambda\ k_B T}})\ -\ 1}\\\\where\\. \ \ \ \lambda=wavelength\\. \ \ \ T=temperature\\. \ \ \ c=speed\ of\ light\\. \ \ \ k_B=Boltzmann\ constant\\. \ \ \ h=Plancks\ constant$