Harmonic average and electromagnetism

[Taturana]

We know that a lot of electrical components associations are calculated using the harmonic average.

If we have parallel resistors we use the harmonic average. If we have serial capacitors we use the harmonic average too and so on...

But my question is: why the harmonic average? what does the harmonic average represents? why not any other type of average?

Could someone explain me that?

Thank you

[0xDEADBEEF]

If you have resistors you see that you simply add the conductance because you have two paths for the current, that is 1 divided by the resistance. Whenever you have to add the inverses of a quantity this behavior leads to the harmonic average.

[Dickfore]

Actually, we don't have the harmonic average. We have n times less than the harmonic average, where n is the number of resistors in parallel.