## Planck constant

Variant of Planck's constant

Physics a universal constant (

*h*) which gives the ratio of a quantum of radiant energy (*E*) to the frequency (ν) of its source: it is expressed by the equation*E*=*h*ν, and its approximate numerical value is 6.626 × 10 joule secondoften Planck constant

Origin of Planck's constant

after Max (Karl Ernst Ludwig) Planck