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.
Prior to Faraday and Henry, the correlation between electricity and magnetism had already been established in the early 19th century. Hans Christian Oersted and Andre-Marie Ampere were some of the major pioneering contributors to the development of the science of electromagnetism.