Poynting's theorem

Poyn·​ting's theorem | \ ˈpȯintiŋz- \

Definition of Poynting's theorem

: a statement in electromagnetic theory: the transfer of energy by an electromagnetic wave is at right angles to both electric and magnetic components of the wave vibration and its rate is proportional to the vector product of their amplitudes

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for Poynting's theorem

after John H. Poynting †1914 English physicist, its originator

Keep scrolling for more

Learn More about Poynting's theorem

Statistics for Poynting's theorem

Cite this Entry

“Poynting's theorem.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Poynting%27s%20theorem. Accessed 19 Jan. 2021.

Comments on Poynting's theorem

What made you want to look up Poynting's theorem? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Words of Snow and Ice Quiz

  • image1037863653
  • Which of the following refers to thin, bending ice, or to the act of running over such ice?
True or False

Test your knowledge - and maybe learn something along the way.


Anagram puzzles meet word search.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!