A problem involing an LC circuit

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Homework Help Overview

The discussion revolves around an LC circuit consisting of a 31 mH inductor and a planar capacitor. Participants are tasked with determining the electrical permittivity of the insulator between the capacitor plates, given specific parameters such as peak current and voltage.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the relationships between peak current and peak voltage in the context of the LC circuit. There are inquiries about which equations can be used to connect these quantities, as well as considerations of energy stored in the inductor and capacitor.

Discussion Status

Some participants have provided guidance on potential equations to consider, while others are questioning the rationale behind selecting specific equations. There is an ongoing exploration of the relationships within the circuit without reaching a consensus.

Contextual Notes

Participants are encouraged to verify their equations and unit conversions, indicating a focus on ensuring accuracy in their approach. There is an emphasis on understanding the underlying principles rather than simply applying formulas.

funoras
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Homework Statement


There's an LC circuit that's made of an 31 mH inductor and a planar capacitator. The surface of the plate is 20cm^2 and the distance between the plates is 1 cm. What is the electrical permittivity of the insulator between the plates , if the peak current is 0,2mA and the peak voltage 10V
L=31mH=3.1*10^-2 H
A=20cm^2=2*10^-3 m^2
d=1cm=0,01 m
Imax=0,2mA=2*10^-4 A
Vmax=10V
ε - ?

Homework Equations


C=q/V
C=εA/d



The Attempt at a Solution

 
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funoras said:

Homework Statement


There's an LC circuit that's made of an 31 mH inductor and a planar capacitator. The surface of the plate is 20cm^2 and the distance between the plates is 1 cm. What is the electrical permittivity of the insulator between the plates , if the peak current is 0,2mA and the peak voltage 10V
L=31mH=3.1*10^-2 H
A=20cm^2=2*10^-3 m^2
d=1cm=0,01 m
Imax=0,2mA=2*10^-4 A
Vmax=10V
ε - ?

Homework Equations


C=q/V
C=εA/d



The Attempt at a Solution


Your unit conversions look okay to me.

Now, what equations can you use to relate the peak current in the LC circuit to the peak voltage? When you have peak series current, what is the voltage across the capacitor? When you have peak voltage across the capacitor, what is the current through the inductor?
 
maybe W=LI^2/2 and W=q^2/2C ?
 

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