Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the construction of Tesla transformers. Period of oscillation and
  self-inductance of the coil. (Zur construction von Teslatransformatoren.
  Schwingungsdauer und Selbstinduction von Drahtspulen)   English Translation of Paul Drude's 1902 investigation into the factors
affecting the self-resonance of single-layer solenoid coils. The ratio of the
self-resonant half-wavelength to the conductor length is is found to be
principally dependent on the height-to diameter ratio of the coil and the
dielectric constants of any insulating materials involved in the construction.

23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom