Number that characterizes a materials ability to become magnetized. Light or an electromagnetic wave in which the vibrations of the electric field lie in one plane and are perpendicular to the direction of travel. Series of four related equations that summarize the behaviour of electric and magnetic fields and their interactions. Radio wave in which the information is carried by increasing and decreasing the frequency of the wave. Materials that exhibit doubly refractive properties while under mechanical stress. A) B) C) D) E) F) G) H) I) J) amplitude modulated radio electric permittivity electromagnetic spectrum electromagnetic wave frequency modulated radio magnetic permeability Maxwell's equations photoelastic plane polarized triangulation