Planck's constant

Planck's constant (plängks) [key], fundamental constant of the quantum theory. It is represented by the letter h and has a value of 6.63 × 10 - 34 J-sec. The combination h /2π, denoted by h (called "h-bar"), occurs frequently.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on Planck's constant from Fact Monster:

See more Encyclopedia articles on: Physics