Question

Explain the importance of Maxwell’s correction.

Answer 1

1. Ampere’s law says that only an electric current can produce a magnetic field. If Ampere’s law alone is true, there will not be any radiation.
2. Maxwell’s correction term `(mu_0epsilon_0 ("d"phi_"E")/"dt")`
3. In ampere’s law ensures that time-varying electric field or displacement current can also produce a magnetic field.
4. Though conduction current is zero in an empty space displacement current does exist. So Maxwell equation becomes
   `oint vec"B" * vec"dI" = mu_0epsilon_0 ("d"φ_"E")/"dt"`
5. Faraday’s law this time-varying magnetic field produces again time-varying electric field and so on.
6. The coupled time-varying electric and magnetic fields travel through empty space with the speed of light and is called an electromagnetic wave.
7. Even though Maxwell initially started with a purely symmetry argument his correction term explains one of the important aspects of the universe namely the existence of electro magnetic waves.