Classical electromagnetism

  • Classical electromagnetism is a theory of physics that describes the interaction of electric and magnetic fields at macroscopic scales. It was developed in the late 19th century by physicists such as James Clerk Maxwell and Michael Faraday. Classical electromagnetism precedes quantum physics.
  • Classical electromagnetism is based on the idea that electric charges and electromagnetic fields are continuous and smooth. It does not take into account the quantization of energy or the wave-particle duality of matter.
  • Charged particles create electromagnetic fields, which in turn exert electromagnetic forces on other charged particles.
  • The four Maxwell equations are:
    • Gauss’s law for electricity: The electric flux through a closed surface is proportional to the total electric charge enclosed by the surface.
    • Gauss’s law for magnetism: There are no magnetic monopoles, and the magnetic flux through a closed surface is always zero.
    • Faraday’s law of induction: A changing magnetic field produces an electric field.
    • Ampere’s circuital law with Maxwell’s correction: A changing electric field or an electric current produces a magnetic field.
  • These equations can be used to describe a wide range of phenomena, from the propagation of electromagnetic waves to the operation of electrical and electronic devices. They are also used in many different fields, including engineering, medicine, and astronomy.