Finding the maximum value of current through the inductor

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SUMMARY

The discussion centers on calculating the maximum current through an inductor in an electrical circuit involving a capacitor and an inductor. The user derived the charge on the capacitor as ##q(t) = CE(1 - \cos(\frac{t}{\sqrt{LC}})## and found the current at time t0 to be ##\frac{CE}{\sqrt{LC}}##. However, the user encountered a discrepancy when equating the total energy of the circuit, CE², to the energy stored in the inductor, ½L(Imax)². The resolution indicates that the assumption that all energy is in the inductor at maximum current is incorrect.

PREREQUISITES
  • Understanding of electrical circuits involving inductors and capacitors
  • Familiarity with the loop equation for RLC circuits
  • Knowledge of energy conservation in electrical systems
  • Ability to differentiate equations involving charge and current
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  • Study the principles of energy conservation in RLC circuits
  • Learn about the behavior of inductors and capacitors in transient analysis
  • Explore the derivation of the loop equation in RLC circuits
  • Investigate the conditions under which energy is transferred between capacitors and inductors
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Electrical engineering students, circuit designers, and anyone studying transient responses in RLC circuits will benefit from this discussion.

Rick001
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Homework Statement


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Homework Equations

The Attempt at a Solution


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I got the first 2 parts, but I'm having trouble with the last one. For the time the switch S1 is closed, I derived ##q(t) = CE(1 - \cos(\frac{t}{\sqrt{LC}}))##, by writing the loop equation ##\frac{E}{L} - \frac{1}{LC}q = \frac{d^2 q}{dt^2}##, from that we get charge on the capacitor after t0 to be CE and differentiating my expression, we get current at t=t0 to be ##\frac{CE}{\sqrt{LC}}##, after closing S2 and opening S1, we have a loop where the inductor has a current ##\frac{CE}{\sqrt{LC}}## flowing through it and one capacitor has a charge CE, the other is uncharged. Now for the third part of the question, I tried finding the total energy of the components currently connected, we get a total of CE², I thought equating this to ½L(Imax)² would give me the answer, but none of them match. Why does this not work? Where is my working wrong? The answer for the last part is given as (c)
 

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Welcome to PF!

Rick001 said:
we get a total of CE², I thought equating this to ½L(Imax)² would give me the answer, but none of them match.
You are assuming that when the current is at its maximum, all of the energy is in the inductor.

All of your other work looks correct to me.
 

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