Electric Flux (and Magnetic Flux)

The following is mostly relevant for group 10020 (thursday).

There is an essential difference between electric and magnetic fields. The flux of the electric field is expressed through Gauss’ law for any closed surface S:

,

where Q is the enclosed charge: Electric charges are sources of the electric field. What about the magnetic field? Here we have:

What are then sources of magnetic fields?

Below is a video lecture of our friend Prof. Walter Lewin of MIT (course 8.02, Physics I: Electricity and Magnetism, spring 2002). I will later add a lecture which gives an answer to the above question..

Topics covered in this lecture:

Electric flux — Gauss’ law