Planck's constant
Telecommunications
The constant of proportionality, represented by the symbol h, that relates the energy E of a photon with the frequency 
of the associated wave through the relation E = h, where h = 6.626 × 10-34 joule•second.
The constant of proportionality, represented by the symbol h, that relates the energy E of a photon with the frequency of the associated wave through the relation E = h, where h = 6.626 × 10-34 joule•second.