Tag Archives: electromagnetism

Online lectures from MIT with Walter Lewin

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If you have missed out on some of the lectures or feel you could need a second view on some subjects, we recommend having a look at Walter Lewin’s lectures from MIT:

Our syllabus is not the same as in their course, but some lectures are very relevant. For instance there are lectures on Gauss law, electric flux, magnetism and much more that will follow in our course too.

Spending some time watching a few lectures when you have spare time or are tired of reading can help you grasp concepts that you find hard to understand. It could also be very inspiring!

Should you find some lectures especially useful, don’t forget to tip your fellow students about it by leaving a comment below.

Note on the magnetic vector potential

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Magnetic dipole (Source: Wikipedia*)

In electrostatics we found it very convenient to introduce the concept of the electric potential. It gave us a straight forward way of calculating electric fields without doing any vector calculations or using any symmetry arguments. Can we introduce something similar for magnetic fields?  It turns out that because magnetic fields are divergence less we can find a vector potential who’s curl gives us the magnetic field! Even though this magnetic vector potential is not as useful as the electrostatic potential in elementary applications, it turns out to be of major importance in electrodynamics as well as classical mechanics and quantum mechanics. It might therefore be a good idea to get familiar with the concept and some of it’s properties already, especially if you are taking a degree in physics. In this note I explain how to find the vector potential, the concept of a gauge transformation and it’s fundamental equations relating it to currents in both electrostatics and electrodynamics. Read more here:

* Image found at http://en.wikipedia.org/wiki/File:VFPt_dipole_magnetic3.svg / CC BY-SA 3.0