CHAMPVA is a Department of Veterans Affairs program; TRICARE is a regionally managed health care program for active duty and retired members of the uniformed services, their families, and survivors. In some cases a Veteran may appear to be eligible for both/either program on paper.
Quick Answer. Michael Faraday discovered the law of electromagnetic induction in 1831. He realized that current in a circuit can be induced by changing the magnetic field. Faraday tested it by wrapping a paper cylinder with a wire and connecting the coil to a galvanometer. Faraday then moved the magnet back and forth inside the cylinder.
The recognition of electromagnetism, the unity of electric and magnetic phenomena, is due to Hans Christian Ãrsted and AndrÃ©-Marie AmpÃ¨re in 1819-1820; Michael Faraday invented the electric motor in 1821, and Georg Ohm mathematically analysed the electrical circuit in 1827.