DOC.
14
PROOF OF
AMPERE'S
CURRENTS
187
710
Ordi-
nates
1/
b2
-
l/ b2
V
b
1-b2
1-b2
15 0,0911 0,812
1,32
0,120
12 0,152 0,649 0,853 0,130
9
0,221 0,488 0,560 0,124
7
0,293 0,380 0,413 0,121
5
0,403 0,271 0,280 0,114
4
0,489 0,217 0,222 0,108
3
0,618 0,163 0,165 0,0957
The last column
shows that for the
greater deviations,
not less
than
7
mm, the
curve agrees satisfactorily with theory,
v
1/b2/1-b2
being
sufficiently
constant. If
we pass on
to
smaller ordinates
this
quantity seems
to
decrease
very
rapidly.
It
must
be remarked how-
ever
that the small
ordinates
cannot
be
measured with
sufficient
precision.
We shall
therefore
use
the first
four
ordinates
only.
The
mean
of the
numbers
deduced from them
is
i/-i
V

0,124.
Further it
follows
from
the
curve
that
1,85
M
145,4
0,320.10-2.
The
moment of inertia of
the
vibrating
system was
determined
by
measuring
the
change
of
frequency
produced
by
the addition of
a
small moment
of
inertia, which
is
accurately
known.
We
found
1)
for
it
Q
=0,0126
If
now we
take 1300 for the
magnetization
(calculated
from
the
hysteresis
curve
of the material and the
constants
of
the
coil)
we
find
for
the
magnetic
moment
of the
cylinder
Is
=
470.
With these numbers
equation
(17)
leads
to the value
1)
It
may
be mentioned here
that,
assuming a pure cylindrical form, we
calcu-
lated for
the moment
of
inertia of the
cylinder
without the
glass
tube and the
little mirror
Q=0,0102.
[16]
[17]
[18]
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