How does current flow through a capacitor?

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Homework Help Overview

The discussion revolves around the behavior of current in relation to capacitors, particularly in DC circuits. Participants explore whether current flows through a capacitor and how charge builds up on its plates, considering the implications of the dielectric and the role of voltage.

Discussion Character

  • Conceptual clarification, Assumption checking, Exploratory

Approaches and Questions Raised

  • Participants question the fundamental nature of current flow through a capacitor, with some expressing confusion about the accumulation of charge and the implications of the capacitor's structure. Others discuss the conditions under which current might flow and the relationship between charge, capacitance, and voltage.

Discussion Status

The discussion is ongoing, with some participants providing clarifications about the behavior of current and charge in capacitors. There is a mix of interpretations regarding the flow of current and the effects of voltage, with no explicit consensus reached yet.

Contextual Notes

Participants are considering the effects of applying DC voltage and the conditions under which the dielectric might break down, as well as the implications of charge accumulation on the capacitor plates.

thesuxx
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this is a fundamental thing that has been bothering me
does current even flow through a capacitor at all??
the plates are separated right, so I would think no

I can imagine the electrons coming out of the battery and collecting on the capacitor plate, and pushing the ones on the other side, but will electrons collect indefinitely on one side, and create a sort of vacuum of electrons of the other side since they are absorbed into the battery or what? (this is probably wrong right?)
can someone explain to me what what is going on?
 
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The current would only flow through if the dielectric of the electric field is broken. At that point it isn't capacitative.

Normally though the charge builds up on either side and the current in the entire circuit goes to zero exponentially. The charge is stored on the capacitor.
 
for a capacitor in a DC circuit (if the dielectric between the plates does not break down), a battery will transfer electrons to one plate while depleting electrons from the other. this process produces a Voltage between the plates. this charge transfer will stop when a total charge Q has been transferred such that:

[tex]Q \ = \ C*V[/tex]

where C is the capacitor's capacitance (usually a constant with units of Farads) and V is the voltage built up between the plates (usually the battery voltage in a DC circuit).
 
Last edited:
thank you, that helps clear things up
 
When you apply a D.C Voltage in parallel with capacitor , a potential difference is applied across the plates of the capacitor, due to this potential difference , the electron start moving towards hgher potential, this is how the current starts flowing through the capacitor. Whenever you think about current , think about the movement of electrons.

Further, as current through starts increasing , the electric field developed which stops further accumulation of electrons. Therefore the current keeps on decreasing in the circuit while charge resting on the plates starts increasing . The charge accumulation increases exponentially and attains an equilibrium situation at infinity time.
 

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