What is Planck's constant? - Definition from WhatIs.com

Definition

Planck's constant

Part of the IT standards and organizations glossary:

Planck's constant, symbolized h, relates the energy in one quantum (photon) of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 x 10-34 joule-seconds. In the centimeter-gram-second (cgs) or small-unit metric system, it is equal to approximately 6.626176 x 10-27 erg-seconds.

The energy E contained in a photon, which represents the smallest possible 'packet' of energy in an electromagnetic wave, is directly proportional to the frequency f according to the following equation:

E = hf

If E is given in joules and f is given in hertz (the unit measure of frequency), then:

E = (6.626176 x 10-34) f

and conversely:

f = E / (6.626176 x 10-34)

Also see electromagnetic field, energy, frequency, SI, and Table of Physical Units and Constants.

This was last updated in September 2005
Posted by: Margaret Rouse

Related Terms

Definitions

  • NGO (non-governmental organization)

    - NGO definition: A non-governmental organization (NGO) is a citizen-based association that operates independently of government, usually to deliver resources or serve some social or political purpose. (WhatIs.com)

  • framework

    - In computer systems, a framework is often a layered structure indicating what kind of programs can or should be built and how they would interrelate. (WhatIs.com)

  • farad (F)

    - The farad is the standard international unit of capacitance. Both the farad and Faraday's constant are symbolized by the capital letter F; however they are different. Faraday's constant is a measur... (WhatIs.com)

Glossaries

  • IT standards and organizations

    - Terms related to information technology (IT) standards, including definitions about IT organizations and words and phrases about policies and compliance.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About Planck's constantPowered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.