DOC.
39
227
Thus,
in this
case
there
applies
the
law
of chance
errors
to
the
deviations
E.
For
the
mean
value of the
work
A
one
obtains
A
=
1
R
A
.
2 N
1
'
Hence,
the
mean
value of the
square
of
the
fluctuation
e
of
a
para-
meter
A
is
such
that, in
order to
change
the
parameter
A
from
A0
to
A0
+
E2
at constant
energy
of
the
system,
the external
work
A
that
one
would have to
apply,
if
thermodynamics were
strictly
valid,
equals
1/2 R/N
T
(i.e.,
one-third
of
the
mean
kinetic
energy
of
one
atom).
If
one
inserts the numerical values for
R
and
N, one
obtains
approximately
A =
10-16T.
We
shall
now
apply
the result obtained
to
a
short-circuited condenser
of
(electrostatically
measured)
capacitance
c.
If
p2
is the
mean
(electrostatic)
potential difference that the condenser
assumes as a
result of
molecular
disorder,
then
J
=
^
cF
=
10-167*
.
We assume
that the condenser is
an
air condenser
consisting of
two
interlocking plate
systems
containing
30
plates each.
The average
distance
between each plate
and
the
adjacent
plate of the other
system
shall
be
1
mm.
The
size of the plates shall
be
100 cm2. The
capacitance
c
is then
about
5,000.
At
normal temperature
one
then obtains
p2
stat.
=
3.4
x
10-9.
[6]
Measured
in volts,
one
obtains
[5]