Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The genesis of the internal resistance of a battery -- a physical
  perspective   The standard exposition of the internal resistance of a battery, that a
battery comprises a source of emf in series with an internal resistance, as
given in engineering and physics text-books, is lacking in proper explanation.
It is treated merely as an experimental fact, and not something that should
follow from logic. The battery has a tendency to maintain electric potential
difference across its terminals equal to its chemical potential, and in an open
circuit, when no current flows, these two do match. However in a closed
circuit, a drop in electric potential across the battery terminals is
inevitable for a steady flow of electric current throughout the circuit,
because the chemical reactions driving the electric current within the battery
can proceed only if the electric potential at its terminals differs from the
chemical potential. It is shown that for small voltage changes, the current
passing through the battery is linearly proportional to the change in potential
from the open-circuit value (i.e., its chemical potential), giving rise to a
semblance of an internal resistance in series with the external resistance. It
follows that a battery {\em has to have} an internal resistance in order to
function as a power source. It is also shown that Thevenin's theorem does not
make our results superfluous, in fact our results are presupposed in its
derivation.

5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
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The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol