Reasoning for common circuit symbols

Question

I would like to know where and why the common quantity symbols for impedance (Z), resistance (R), reactance (X), admittance (Y), conductance (G), and susceptance (B) were first defined. It seems trivial to chose R to denote resistance, but I have not been able to find primary sources for these quantities. For example, is the complex impedance Z derived from the commonly used notation \$z = x + iy\$? In 1894, Steinmetz defined impedance as \$U = r - js\$ and admittance as \$Y = \rho + j\sigma\$ [1].

On a side note, this is my current understanding of the reasoning for some of the commonly used and related symbols:

• (R)esistance
• (C)apacitance
• Inductance was named after (L)enz
• (q)uantized electric charge
• (I)ntensity of current
• (V)oltage
• (E)lectric field
• electric (D)isplacement current

[1] https://ieeexplore.ieee.org/document/4763808

Answer 1

I found no article summarising the origins of all electrical symbols. After a short research, I found that it will be not a small work to get all the detailed origins. Here I just write for a few symbols that I think to worth to mention.

Resistance symbol R

Yes, it stands for the word "Resistance". It is not trivial when it was first started to use. In Ohm's original article in 1820s, he did not use symbols like E, V, I, and R. He used other symbols for his experiment notes and articles:

, here,

$$ X = \frac{a}{b + x} $$

, which is equivalant to the modern symbol notations:

$$ I = \frac{U}{r + R} $$

Current symbol I

The start date of using is not trivial just like R, it is believed that the symbol is originated from a French word "intensite". Read more on Wikipedia - Electric current

Electric field symbol E

Maxwell used several symbols that are same as modern usage including E for elctric field. I'm not sure who started to use the same symbol before Maxwell.

Impedence Z

Z does not stand for anything. It is believed that it's choosen just for easier remembering.

The AC equivalent to Ohm's law was first shown by Oliver Heaviside in 1886. He might introduce the concept "impedence". But I could not find his original article to see if he used symbol Z for impedence.

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I think this question is hard to answer correctly in a single answer post. If someone discover more information about other symbols, another answer can be attached.