RC Circuit with alternating voltage source

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SUMMARY

The discussion centers on analyzing an RC circuit with an alternating voltage source represented by V=V0ejwt. The current (I) in the circuit is determined using the equation I=C*dv/dt, where 'v' specifically refers to the voltage across the capacitor. Participants confirm the applicability of Kirchhoff's Voltage Law (KVL) in this context and clarify that the voltage source is treated as a phasor, focusing on the real part V0cos(ωt) for practical calculations. The differential equation derived from KVL is a key point of confusion for the participants.

PREREQUISITES
  • Understanding of RC circuits and their components
  • Familiarity with complex numbers and phasors
  • Knowledge of Kirchhoff's Voltage Law (KVL)
  • Basic differential equations and their applications in circuit analysis
NEXT STEPS
  • Study the application of phasors in AC circuit analysis
  • Learn how to solve differential equations related to RC circuits
  • Explore the implications of Kirchhoff's Voltage Law in AC circuits
  • Review the relationship between voltage and current in capacitors
USEFUL FOR

Electrical engineering students, circuit designers, and anyone involved in analyzing AC circuits with capacitive components.

sun18
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Homework Statement


I'm supposed to find the current in a circuit with a voltage source, capacitor, and resistor in series. The voltage source is described by V=V0ejwt.
Here, j is the complex number j2=-1, and i is the current

Homework Equations


I=C*dv/dt

The Attempt at a Solution


I have several sources of confusion with this question. First, in the equation I=C*dv/dt, does that v refer to the voltage source, or specifically the voltage drop across the capacitor? Can I use Kirchoff's voltage law with this type of circuit? I tried this and got:

V0ejwt - iR - q/c = 0
Then taking the time derivative of the equation:

V0jwejwt - R*di/dt - i/c = 0
I then have no idea how to solve this differential equation. Even rewriting with euler's identity:
V0jw[cos(wt)+jsin(wt)]=R*di/dt+i/c

Any help would be greatly appreciated.
 
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I suspect that the ##V = V_o e^{j \omega t}## is meant to be a phasor representation for the input. Have you covered phasors yet? If so you're meant to deal with the real portion of the resulting voltage, which in this case would be ##V_o cos(\omega t)##.

Yes, the v in I = C*dv/dt represents the voltage across the capacitor.

Yes, Kirchhoff's Voltage Law (KVL) can be applied as you have done.
 
We haven't covered phasors yet but I read ahead and it makes sense now.
Thank you for the response.
 

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