Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Why two formulas for the electric field intensity and the magnetic
  induction created by a uniformly moving point charge?   A derivation of the electric field intensity and of the magnetic induction
generated by a uniformly moving point charge is presented. The derivation is in
accordance with the fact that the electric and magnetic fields of moving charge
are propagating from the charge with speed $c$ in empty space. The derivation
is tailored for a special audience who knows the transformation of space, time
and fields and Coulomb's law in the rest frame of the point charge. It avoids
the use of Maxwell's equations and the concept of retarded potential.

13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg