Derivation of mechanism of charging capacitor

AI Thread Summary
The discussion focuses on deriving the mechanism of charging a capacitor in a circuit with a battery, capacitor, resistor, and switch. The user begins with the equation Q=CVc and differentiates it with respect to time, applying Kirchhoff's law to relate the voltages in the circuit. A key question arises regarding the integration of potential difference from 0 to V, which is clarified by understanding that the capacitor starts with no potential difference when uncharged and reaches the applied potential as it charges. The user confirms that their thought process is correct, recognizing the relationship between charge accumulation and the increasing potential difference across the capacitor. Overall, the conversation emphasizes the mathematical derivation and the physical principles governing capacitor charging.
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I am trying to derive the mechanism of a charging capacitor , V=Vo(1-e^(-t/CR))

sorry , i couldn't upload the diagram here so i will briefly describe it , its a circuit with a battery (Vo) , connected to a capacitor (Vc) , and resistor (VR) and also a switch , all in series .

i started with

Q=CVc , then differentiate w r t to time t ,

\frac{dQ}{dt}=\frac{d}{dt}(CV_c)=C\frac{dV_c}{dt}

using kirchhoff law , V_o=V_R+V_c (Refer to the diagram)

=IR+V_c

=CR\frac{dV_c}{dt}+V_c

\frac{1}{RC}dt=\frac{dV_c}{V_o-V_c}

Integrate from time , 0 to t ,

and also integrate from potential difference , 0 to V ,

Here is my question , why integrate the pd from 0 to V ??

I understand that the capacitor is initially at a constant potential difference , then when the switch is closed , the amount of charge increases , followed by the pd between the capacitors .

is my thought process even correct ? Thanks in advance .
 
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When the switch is closed , the amount of charge increases. PD across the capacitor also increases until its PD is equal to the applied PD.
 
rl.bhat said:
When the switch is closed , the amount of charge increases. PD across the capacitor also increases until its PD is equal to the applied PD.

thank you , so when the capacitor is not charged , there is no pd , and when its charged , the pd becomes v (the applied pd) , so integrate within this range . Thanks !
 
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