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every conductor has inherent capacitance

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PG1995

Active Member
Hi

A capacitor has capacitance due to different types of charge of its plates. Okay. This is understandable. A conductor is said to have uniform spread of charge and charges (i.e. electrons) can flow one place to another to neutralize an imbalance of charges. Still, it is said every conductor has an inherent capacitance. How is this possible? In case of a capacitor energy is invested to create an imbalance of charge; there is nothing 'natural' in this case. How can a conducting wire have any capacitance? Please help me with it. Thank you.

Regards
PG
 
A capacitor has two plates with an insulator in between.
Your 'conductor' or wire is one plate. The insulator is air. The second plate is the universe, hour hand, the walls & floor, every thing around.

I have a meter that can measure 0.02pF. It will measure a 1 inch square piece of copper and the capacitance changes with how close it is to the bench top.
 
Not only does a wire have capacitance, it has inductance as well.

It gets worse, a wire with low resistance, can under the right set of circumstances behave like an insulator.

JimB
 
A antenna (wire) can be built to resonant at some frequency. So the wire has L and C and R. The wire also has a delay which is related to the speed limit.
 
Thank you, Ron, Jim.

Okay. Now I understand that capacitance can exist between a conductor and some nearby object such as wire or ground. But still to have some capacitance one of the 'plates' should have uneven spread of the charge so that it can disturb the charge distribution in a nearby object. Say, the conducting wire has an evenly spread charge throughout it, then how can it affect anything nearby to develop capacitance when it is a neutral conducting material.

I have also read that capacitance can exist between different sections of a same wire. For example, please have a look on the linked scan: https://img11.imageshack.us/img11/8789/inductrcapacitance.jpg

Please keep your explanation simple and don't make things more complicated. Thanks a lot.

Regards
PG
 
PG,
The link has a very good picture. Wires inside a coil have capacitance. That is why an inductor has a self resonant frequency. coil=R+C+L
Life is not black/white or good/bad. Even pure water is not pure.
Every conductor resists some and ever insulator conducts (leaks) some.
'The pope cheats at poker.' Maybe not cheats but he wins too much on Sundays.
 
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