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Homework Help: Capacitance Problem

  1. Mar 25, 2005 #1
    Hi. I have this seemingly easy problem that I cannot get the right answer to! Here it is:

    A parallel-plate capacitor has circular plates of 6.00 cm radius and 2.00 mm separation.
    Calculate the capacitance.

    Ok, so I thought the formula for capacitance was [(epsilon)_0 x Area]/distance = capacitance

    So I tried: [(8.85E-12 F/m)(4(pi)(0.06m)^2)]/0.002m = 200.2 pF

    I cannot figure out what I am doing wrong. That formula is in the book! Am I overlooking something? Thanks in advance for any help you can give!

    Beverly
     
  2. jcsd
  3. Mar 25, 2005 #2
    The area of a circle isnt 4*pi*r^2. :)
     
  4. Mar 27, 2005 #3
    Aggh!! I'm such an idiot!! What was I thinking? Haha, Thanks!!
     
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