a: a fundamental physical force that is responsible for interactions between charged particles which occur because of their charge and for the emission and absorption of photons, that is about a hundredth the strength of the strong force, and that extends over infinite distances but is dominant over atomic and molecular distances —called also electromagnetic force — compare gravity 3a(2), strong force, weak force
b: a branch of physical science that deals with the physical relations between electricity and magnetism
: physics dealing with the relations between electricity and magnetism
Branch of physics that deals with the relationship between electricity and magnetism. Their merger into one concept is tied to three historical events. Hans C. Orsted's accidental discovery in 1820 that magnetic fields are produced by electric currents spurred efforts to prove that magnetic fields can induce currents. Michael Faraday showed in 1831 that a changing magnetic field can induce a current in a circuit, and James Clerk Maxwell predicted that a changing electric field has an associated magnetic field. The technological revolution attributed to the development of electric power and modern communications can be traced to these three landmarks.