Help Me Find the Capacitance: A Stumped Student's Story

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    Capacitance
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Homework Help Overview

The discussion revolves around a problem related to capacitance involving the arrangement of capacitor plates. The original poster describes a scenario where they have separated plates to form three capacitors and are unsure about calculating the resultant capacitance.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to analyze the configuration of the capacitors, considering different arrangements and questioning the validity of ignoring certain plates. They express confusion over the series and parallel relationships between the capacitors.

Discussion Status

Some participants are engaging in clarifying the arrangement of the capacitors, with one suggesting that the original poster's interpretation of the circuit is correct, while another insists on a different perspective based on a textbook answer. There is an active exploration of the assumptions regarding the series and parallel configurations.

Contextual Notes

The original poster references a textbook answer that conflicts with their own calculations, indicating a potential misunderstanding of the capacitor arrangement. There is also a mention of uncertainty regarding the relevance of the end plates in the configuration.

cupid.callin
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Hi again!

I got stuck in this question (Pic), the original question is the fig. 1. I then arranged the charges on the plates (fig 2) and then separated the plates to form three capacitors. Now I just don’t know what the capacitance will be and how to find it!
First I thought to ignore the two plates at 2 ends. Then the two capacitors on right will be in parallal and their resultant in series with the last one… then answer comes out to be 2C/3 … which is wrong!
According to the book’s answer, all three capacitors will be in series, to get capacitance as C/3 …
Please tell me how are three capacitors in series, and can I really ignore the end plates!
 

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Please someone help!
 
They are not in series. Your equivalent circuit on the right is correct. Between which points do you need the resultant capacitance?

ehild
 
No, I am telling you they are in series because the net capacitance comes out to be (acc. to book) C/3
 
some help?
 

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