Understanding Capacitors in DC Circuits

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SUMMARY

This discussion focuses on the behavior of capacitors in DC circuits, specifically in a series configuration with a resistor. When a DC voltage source is applied, the capacitor initially allows current to flow until it is fully charged, despite the dielectric preventing current from passing through the capacitor itself. Once charged, the capacitor can discharge through a parallel load, such as a light bulb, demonstrating that current can flow in the circuit even though it does not pass through the capacitor. This highlights the importance of understanding charge flow and circuit completion in capacitor-resistor configurations.

PREREQUISITES
  • Basic understanding of DC circuits
  • Knowledge of capacitor behavior in electrical circuits
  • Familiarity with Ohm's Law
  • Concept of charging and discharging in capacitors
NEXT STEPS
  • Study the charging and discharging curves of capacitors in RC circuits
  • Learn about the role of dielectrics in capacitors
  • Explore the concept of time constant in RC circuits
  • Investigate the effects of different resistor values on capacitor charging times
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Students of electrical engineering, hobbyists working with DC circuits, and educators teaching the principles of capacitors and circuit theory.

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Homework Statement


I have just started learning about capacitors and my question is when you have a DC voltage source connected in a circuit which also has a resistor and capacitor all in series, i.e. a basic charging circuit, is this circuit complete, since there is an air gap or non conductive dielectric in the capacitor there will no flow of current. Let's say to the same circuit we connect a light bulb in parallel to the capacitor than the capacitor will discharge and the light bulb will light up and than go off again. How this be possible if there is no flow current in the circuit since DC current cannot pass through capacitors. How is the circuit formed in this case.
Code:
-------R-----
|                |
V               C
|                |
-------------

-------R------------
|                |        |
V               C      Bulb
|                |        |
--------------------



Homework Equations





The Attempt at a Solution


So in the case of capacitor charging i.e. without the light bulb there will be no current flow in the circuit because the capacitor will not pass DC current, i.e current across resistor R will be zero and in the case of capacitor discharging the current will also be zero since DC current does not flow through capacitor. When you put a capacitor in the DC circuit are you not just creating a break in the circuit than how can this circuit function, i.e. we do not have flow of electrons. The question is what am i missing to understand how the capacitors behave in a DC circuit and how is the circuit completed...
 
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Though current cannot flow through air gap/dielectric in the capacitor, charges can flow from both plates of capacitor (outwards) into the circuit through R and V in order to charge the capacitor. So even in a DC circuit, current flows in the circuit (not through/inside the capacitor) when R and C is connected till C is charged to applied voltage V.
 

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