Logarithm Table

Natural logarithm

When using the component of the capacitor and so on with the electronic circuits,
the logarithm must be computed to look for the electric current which flows through the circuit.
The logarithm computation can be computed with the function computer but I show the tables of logarithm in this page.

The formula is shown below and it looks for the X.
e is the base of the natural logarithm and the value is 2.71828.

n = ex

It becomes the following when changing into the formula which looks for the X.

x = logen

So as not to confuse with the common logarithm("log10" or it is simply expressed with "log"),
"loge" is sometimes expressed with the "ln".
x = ln n
In case of n=1, it becomes x=0 and when the n is less than 1, x becomes the negative value.
When the n is less than 1, it becomes the same as the one to have made x which is due to the value of 1/n negative.

The natural logarithm table (Equal to or less than 1.0)
n logen n logen n logen n logen 0.01 -4.60517 0.26 -1.34707 0.51 -0.67334 0.76 -0.27443 0.02 -3.91202 0.27 -1.30933 0.52 -0.65392 0.77 -0.26136 0.03 -3.50655 0.28 -1.27296 0.53 -0.63488 0.78 -0.24846 0.04 -3.21887 0.29 -1.23788 0.54 -0.61618 0.79 -0.23572 0.05 -2.99573 0.30 -1.20397 0.55 -0.59783 0.80 -0.22314 0.06 -2.81341 0.31 -1.17118 0.56 -0.57982 0.81 -0.21072 0.07 -2.65926 0.32 -1.13943 0.57 -0.56212 0.82 -0.19845 0.08 -2.52573 0.33 -1.10866 0.58 -0.54472 0.83 -0.18633 0.09 -2.40794 0.34 -1.07881 0.59 -0.52763 0.84 -0.17435 0.10 -2.30258 0.35 -1.04982 0.60 -0.51082 0.85 -0.16252 0.11 -2.20727 0.36 -1.02165 0.61 -0.49430 0.86 -0.15082 0.12 -2.12026 0.37 -0.99425 0.62 -0.47803 0.87 -0.13926 0.13 -2.04022 0.38 -0.96758 0.63 -0.46203 0.88 -0.12783 0.14 -1.96611 0.39 -0.94161 0.64 -0.44629 0.89 -0.11653 0.15 -1.89712 0.40 -0.91629 0.65 -0.43078 0.90 -0.10536 0.16 -1.83258 0.41 -0.89160 0.66 -0.41551 0.91 -0.09431 0.17 -1.77196 0.42 -0.86750 0.67 -0.40047 0.92 -0.08338 0.18 -1.71480 0.43 -0.81419 0.68 -0.38566 0.93 -0.07257 0.19 -1.66073 0.44 -0.82098 0.69 -0.37106 0.94 -0.06187 0.20 -1.60944 0.45 -0.79851 0.70 -0.35667 0.95 -0.05129 0.21 -1.56065 0.46 -0.77653 0.71 -0.34249 0.96 -0.04082 0.22 -1.51412 0.47 -0.75502 0.72 -0.32850 0.97 -0.03046 0.23 -1.46968 0.48 -0.73397 0.73 -0.31471 0.98 -0.02020 0.24 -1.42711 0.49 -0.71335 0.74 -0.30110 0.99 -0.01005 0.25 -1.38629 0.50 -0.69214 0.75 -0.28768 1.00 -0.00000

The natural logarithm table (Equal to or more than 1.0)
n logen n logen n logen n logen 1.0 0.00000 3.0 1.09861 5.0 1.60944 25.0 3.21887 1.1 0.09531 3.1 1.13140 6.0 1.79176 26.0 3.25809 1.2 0.18232 3.2 1.16315 7.0 1.94591 27.0 3.29583 1.3 0.26236 3.3 1.19392 8.0 2.07944 28.0 3.33220 1.4 0.33647 3.4 1.22377 9.0 2.19722 29.0 3.36729 1.5 0.40546 3.5 1.25276 10.0 2.30258 30.0 3.40119 1.6 0.47000 3.6 1.28093 11.0 2.39789 40.0 3.68888 1.7 0.53063 3.7 1.30833 12.0 2.48491 50.0 3.91202 1.8 0.58779 3.8 1.33500 13.0 2.56495 60.0 4.09434 1.9 0.64185 3.9 1.36097 14.0 2.63905 70.0 4.24849 2.0 0.69314 4.0 1.38629 15.0 2.70805 80.0 4.38202 2.1 0.74193 4.1 1.41099 16.0 2.77259 90.0 4.49981 2.2 0.78845 4.2 1.43508 17.0 2.83321 100.0 4.60517 2.3 0.83291 4.3 1.45861 18.0 2.89037 200.0 5.29832 2.4 0.87547 4.4 1.48160 19.0 2.94444 300.0 5.70378 2.5 0.91629 4.5 1.50408 20.0 2.99573 400.0 5.99146 2.6 0.95551 4.6 1.52605 21,0 3.04452 500.0 6.21461 2.7 0.99325 4.7 1.54756 22,0 3.09104 600.0 6.39693 2.8 1.02962 4.8 1.56861 23.0 3.13549 700.0 6.55108 2.9 1.06471 4.9 1.58923 24.0 3.17805 800.0 6.68461

Common logarithm

At the electronic circuits, the common logarithm(the logarithm having base 10) is used for the thing except above-mentioned natural logarithm.

n = 10x

x = log10n

This value is used when it expresses the mu factor and so on and compares the two values.
The common logarithm is used for the dB ( decibel ).
The noise to the electric signal sometimes show the 1/1000 or 1/10000 values and so on.
It shows in the dB because the number of the figures increases when displaying just as it is.

In case of the voltage ratio : dB = 20 log10 (V1/V2)

In case of the electric power ratio : dB = 10 log10 (P1/P2)

It represents as -60 dB in case of V1=0.001 V , V2=1 V.

When the voltage ratio is twice, it is 6 dB.
When the electric power ratio is twice, it is 3 dB.

The common logarithm table
n log10n n log10n n log10n n log10n 0.0001 -4.00000 1.0 0.00000 3.0 0.47712 5.0 0.69897 0.001 -3.00000 1.1 0.04139 3.1 0.49136 5.1 0.70757 0.01 -2.00000 1.2 0.07918 3.2 0.50515 5.2 0.71600 0.02 -1.69897 1.3 0.11394 3.3 0.51851 5.3 0.72427 0.03 -1.52287 1.4 0.14612 3.4 0.53148 5.4 0.73239 0.04 -1.39794 1.5 0.17609 3.5 0.54406 5.5 0.74036 0.05 -1.30103 1.6 0.20412 3.6 0.55630 5.6 0.74819 0.06 -1.22184 1.7 0.23045 3.7 0.56820 5.7 0.75587 0.07 -1.15490 1.8 0.25527 3.8 0.57978 5.8 0.76342 0.08 -1.09691 1.9 0.27875 3.9 0.59106 5.9 0.77085 0.09 -1.04575 2.0 0.30103 4.0 0.60206 6.0 0.77815 0.1 -1.00000 2.1 0.32222 4.1 0.61278 6.1 0.78533 0.2 -0.69897 2.2 0.34242 4.2 0.62325 6.2 0.79239 0.3 -0.52288 2.3 0.36172 4.3 0.63347 6.3 0.79934 0.4 -0.39794 2.4 0.38021 4.4 0.64345 6.4 0.80618 0.5 -0.30103 2.5 0.39794 4.5 0.65321 6.5 0.81291 0.6 -0.22184 2.6 0.41497 4.6 0.66275 6.6 0.81954 0.7 -0.15490 2.7 0.43136 4.7 0.67210 6.7 0.82607 0.8 -0.09691 2.8 0.44715 4.8 0.68124 6.8 0.83251 0.9 -0.04575 2.9 0.46239 4.9 0.69019 6.9 0.83885

n log10n n log10n n log10n 7.0 0.84509 9.0 0.95424 20.0 1.30103 7.1 0.85126 9.1 0.95904 21.0 1.32221 7.2 0.85733 9.2 0.96379 22.0 1.34242 7.3 0.86332 9.3 0.96848 23.0 1.36172 7.4 0.86923 9.4 0.97312 24.0 1.38021 7.5 0.87506 9.5 0.97772 25.0 1.39794 7.6 0.88081 9.6 0.98227 26.0 1.41497 7.7 0.88649 9.7 0.98677 27.0 1.43136 7.8 0.89209 9.8 0.99122 28.0 1.44715 7.9 0.89762 9.9 0.99563 29.0 1.46239 8.0 0.90309 10.0 1.00000 30.0 1.47711 8.1 0.90848 11.0 1.04139 40.0 1.60206 8.2 0.91381 12.0 1.07918 50.0 1.69897 8.3 0.91907 13.0 1.11394 60.0 1.77815 8.4 0.92428 14.0 1.14612 70.0 1.84509 8.5 0.92941 15.0 1.17609 80.0 1.90309 8.6 0.93450 16.0 1.20142 90.0 1.95424 8.7 0.93952 17.0 1.23044 100.0 2.00000 8.8 0.94448 18.0 1.25527 1000.0 3.00000 8.9 0.94939 19.0 1.27875 10000.0 4.00000