When an electrically-conducting structure is exposed to a time-varying magnetic field, an electrical potential difference is induced across the structure. This phenomenon is known as electromagnetic induction. ... Faraday's Law describes the generation of electric potential by a time-varying magnetic flux.

What are time varying fields?

In other words, a time-varying electric field is produced by a time-varying magnetic field and a time-varying magnetic field is produced by a time-varying electric field. The first concept was experimentally introduced by Michael Faraday and the second was theoretically introduced by James Clerk Maxwell.

What is time varying field find equation for EM wave propagation?

This is Maxwell's equation (based on Ampere's circuit law) for a time-varying field. The term Jd = ∂D/∂t is known as displacement current density and J is the conduction current density (J = σE)3. ... Without the term Jd, electromagnetic wave propagation (radio or TV waves, for example) would be impossible.