Analogy Between Conductance & Capacitance

AI Thread Summary
The discussion focuses on the analogy between capacitance (C) and conductance (G), emphasizing that while their formulas may seem similar due to algebraic structures in series and parallel configurations, this is not a true analogy. The underlying physical reason for their similarity lies in their relation to transport properties influenced by the electric field. The equations D = εE and J = σE illustrate this connection, leading to the derived formulas C = εA/d and G = σA/d. Additionally, when considering time-harmonic fields, capacitance and conductance become closely related through the concept of complex permittivity. This highlights the deeper relationship between these electrical properties beyond mere algebraic resemblance.
Mo7amed
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Hi all...
I want more information about the analogy between calculating the capacitance C and the conductance G ?
 
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I don't think that's an analogy. The formulas may appear somewhat similar simply because of how things are added in parallel or series, but that's just an algebraic thing.
 
TVP45 said:
I don't think that's an analogy. The formulas may appear somewhat similar simply because of how things are added in parallel or series, but that's just an algebraic thing.

There's a physical reason underlying the similarity of the equations, which is that they are related to transport properties. Whilst this similarity exists for all such properties, these two are particularly similar in that they both relate to the electric field via the constituent equations

D = \epsilon E
J = \sigma E

Following through to C & G, we get

C = \epsilon A / d
G = \sigma A / d

Using basic geometric arguments you can then derive series & parallel relationships.

If one assumes time-harmonic fields these become very closely related through the concept of complex permittivity.
 
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