electromagnetism vs physics

electromagnetism and physics both are nouns.

Word	Noun	Adjective	Verb	Adverb
electromagnetism	Yes	No	No	No
physics	Yes	No	No	No

As nouns, physics is a hypernym of electromagnetism; that is, physics is a word with a broader meaning than electromagnetism:

electromagnetism: the branch of physics concerned with electromagnetic phenomena
physics: the science of matter and energy and their interactions

Other hypernyms of electromagnetism include natural philosophy.

electromagnetism (noun)	physics (noun)
the branch of physics concerned with electromagnetic phenomena	the science of matter and energy and their interactions
magnetism produced by an electric current	the physical properties, phenomena, and laws of something