ElectroDynamic

Electrodynamics is a branch of physics that studies the interactions of electric charges and currents with electric and magnetic fields, and the dynamics of charged particles in those fields. In classical electrodynamics, charges move under the influence of electric and magnetic forces, while the fields themselves propagate and respond to sources. The theory is grounded in Maxwell's equations and the Lorentz force law. Maxwell's equations describe how charges and currents produce electric and magnetic fields and how changing fields propagate as electromagnetic waves. The Lorentz force law specifies the force on a moving charge due to fields. Together, they predict wave propagation at the speed of light and the conservation of energy and momentum via the Poynting vector.

Electrodynamics covers electrostatics, magnetostatics, and their extension to time-varying situations, including media with dielectric and magnetic properties, boundaries, and dispersion. Key concepts include electromagnetic radiation, interference, diffraction, and the interaction of light with matter, as described in classical optics within the electrodynamic framework.

Applications of electrodynamic theory are wide, including transmission lines, antennas, wireless and optical communication, electric motors and generators, transformers, and medical imaging techniques such as MRI. In modern physics, quantum electrodynamics provides the quantum field theoretic description of the electromagnetic interaction, unifying electrodynamics with quantum mechanics and special relativity.