# Planck's constant

Planck's constant*h*) which gives the ratio of a quantum of radiant energy (

*E*) to the frequency (?) of its source: it is expressed by the equation

*E*=

*h*?, and its approximate numerical value is 6.626 × 10 joule second

Origin of Planck's constant

after Planck

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## Planck's constant

noun

**h**

^{−34}joule-seconds.

Origin of Planck's constant

AfterMax Karl Ernst Ludwig**Planck**

**MLA Style**

"Planck\'s constant." YourDictionary, n.d. Web. 09 August 2018. <http://www.yourdictionary.com/planck-s-constant>.

**APA Style**

Planck\'s constant. (n.d.). Retrieved August 09th, 2018, from http://www.yourdictionary.com/planck-s-constant

- (physics) the constant of proportionality (symbol
*h*), relating the energy and frequency of a photon (6.626 x 10^{-34}joule-seconds); also related to the indeterminacy limit in the Heisenberg uncertainty principle; the quantum of action

Named for Max Planck (1858-1947), German theoretical physicist, who discovered it in 1900.

**MLA Style**

"Planck\'s constant." YourDictionary, n.d. Web. 09 August 2018. <http://www.yourdictionary.com/planck-s-constant>.

**APA Style**

Planck\'s constant. (n.d.). Retrieved August 09th, 2018, from http://www.yourdictionary.com/planck-s-constant