electro-magnetism

 magnetism produced by an electric current.  [WordNet 1.5]

 one of the fundamental forces of nature, responsible for both electrical and magnetic phenomena. Called also the electromagnetic force. Formerly believed to be separate phenomena, electricity and magnetism were shown by experiment and theory to be different aspects of the electromagnetic force. It is responsible for the forces generated between magnetically or electrically charged objects, and is the fundamental force responsible for the characteristics of electromagnetic radiation, including light.  [PJC]

 the branch of physics concerned with electromagnetic phenomena.  [WordNet 1.5]