# How to differentiate Capacitance (Italized C) and Coloumbs (regular C) on paper [closed]

I am doing a question on capacitance and coulombs. I got the answer correct, but I was wondering how a physicist, when doing the calculation on paper, would differentiate a C and C?

## closed as primarily opinion-based by Kyle Kanos, ZeroTheHero, Jon Custer, Void, Norbert SchuchJan 8 at 0:25

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• Capacitance is measured in Farads, with an "F". – Hot Licks Jan 5 at 2:05
• When the equation is in terms of symbols, $C$ probably indicates some capacitance. When you are using the equation to calculate something by substituting numerical values for all the symbols, then C is probably the unit (Coulomb) for the value of some symbol that represented a charge. This does not tend to create confusion unless you substitute values for some symbols and not others. – G. Smith Jan 5 at 3:22

I will omit the fact that capacitance is measured in Farads, as I see a more general use to the question. For the sake of this answer I will answer as if we are symbolically manipulating capacitance and use the variable $$C$$.

I usually don't have this issue with capacitance, but when I want to make explicit that I'm using a capital letter that is non italicized what I'll do is put a line under it. For instance I would write $$C$$ for capacitance and $$\underline{C}$$ for coulombs.

Like I said this is probably overkill for capacitance and coulombs, but I think it's useful in a broader context.

Downfalls: If you're writing fast it can get kind of messy if your capital letter appears in the numerator like $$\frac{\underline{C}}{C}$$ and wind up looking awkward, so I only do this if I know it's not going to be an issue.

2$$^{nd}$$ solution:If it is unavoidable and the algebra will get nasty I will write my capital letters as "double struck". So for instance $$\mathbb{C}$$ would be Coulombs in this case, and I just close my eyes and hope that I don't need to mention the complex numbers.

• Or just C for coulombs, C1, C2, ... for different capacitances. – The Photon Jan 5 at 1:35
• That's fair, but I was trying to give an answer that was more general and so may be useful ini a broader context – InertialObserver Jan 5 at 1:36