Basic notes on Physics.
In the series: Note 4.

Subject: Some keypoints of Electricity and Magnetism.

Date : 25 August, 2020
Version: 0.0
By: Albert van der Sel
Doc. Number: Note 4.
For who: for beginners.
Remark: Please refresh the page to see any updates.
Status: just starting.

It describes Electricity, Magnetism, Electrostatics, a bit ElectroDynamics,
all more or less on the level of Highschool Physics (and sometimes a bit beyond that level).

You need a few years of highschool physics and math as a prerequisite. Well, sort of...



Usually, in a classical approach, one may consider stationary electric charge(s), and talk about
the Electric Field, and Electric Force only, and not taking into account any magnetic effects.
Yes, that is a correct approach, since with stationary charges you do not seem to observe any magnetic effects.

However, when charges move, we do not only have the Electric field, but a Magnetic field can be
associated with a moving charge as well.

As we will see later on, if we have a wire, and a electric current flows, it can be shown we have
and Magnetic field as well, which for example can be proved by having a compass somewhere near that wire.

Now, look at this. If you are stationary (in a stationary frame of reference), and some stationary Charge
is present too, you only observe an Electric field. But suppose you are in a frame of reference moving
with a constant speed v, moving towards that Charge. That charge is still in that other frame
of reference (the Charge thinks it's not moving at all). But for you, the situation is the same
as if you are stationary, and the charge is moving towards you. This time, you see a moving charge, and
you observe an Electric Field, as well as a Magnetic field.
What is this ? Sounds a bit weird !

The riddle can be solved when we consider Lorenz transformations. However, what we might have learned already,
is that a better description is that of a integrated ElectroMagnetic Field. And in some circumstances, it seems that
we only have an Electric field.

But to accumulate knowledge, it's best to start out with seperate descriptions, so let's take
the classical route to understand this stuff.


1. The Electric Field and Electric Force.

2. The Magnetic Field and Magnetic Force.

3. Induction, and some important devices.

4. The ElectroMagnetic Field.

5. Quantization of the ElectroMagnetic field.




Just starting this note...