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Homework Help: Negative capacitance?

  1. Jun 8, 2004 #1
    I just need a hint on this.

    2 plates of a capacitor hold +1500 C and -1500 C of charge, respectively, when the potential difference is 300 V. What is the capacitance?

    I know I have to use c=Q/V, but which charge do I use the positive or negative?
  2. jcsd
  3. Jun 8, 2004 #2


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    First of all, you can't have a negative capacitance. Second of all, all capacitors will have both a negatively charged and positively charged side, I'm pretty sure, so you should notice since capacitance is always given positive, that you should give it as a positive value. I didn't really like Electronics, so I can't remember or care to get my textbook, but you can look this stuff up (possibly in your text) and figure out how capacitors work, what voltage is, etc, and that way you'll understand why it's positive.
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