Parallel-Plate Capacitor Question

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SUMMARY

The discussion centers on calculating the maximum charge stored in a parallel-plate capacitor made from aluminum foil and mica. The capacitor dimensions are 3.50 cm wide and 15.0 m long, with a mica dielectric of 0.0225 mm thickness. The dielectric constant of mica is 5.4, and its dielectric strength is 1.00 x 108 V/m. The user initially calculated the area and capacitance correctly but misapplied the equations for voltage and charge, leading to an incorrect maximum charge value of 8.6 x 10-5 C.

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Homework Statement



A parallel-plate capacitor is made from two aluminum-foil sheets, each 3.50 cm wide and 15.0 m long. Between the sheets is a mica strip of the same width and length that is 0.0225 mm thick.

What is the maximum charge that can be stored in this capacitor? (The dielectric constant of mica is 5.4, and its dielectric strength is 1.00* 10^8 V/m.

Homework Equations



C=(Eo*A)/d
V=Ed=(Eo/K)*d

The Attempt at a Solution



First I calculated A from the given dimensions, 0.525 m^2. Then I calculated C with [(8.85*10^-12)(0.525)]/(2.25*10^-5 m). Next, I tried to calculate V by taking the dielectric breakdown value of 1.00*10^8 and dividing by the dielectric constant 5.4. I then multiplied that value by the distance, 2.25*10^-5 m giving me 416.67 V. I multiplied V*C to find Qmax. The value is 8.6*10^-5 -- for some reason this isn't right.

Where did I go wrong?

Thanks!
 
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Lovergoo said:

Homework Equations



C=(Eo*A)/d
V=Ed=(Eo/K)*d


The Attempt at a Solution



One of these equations are not correct for a capacitor with a dielectric. They should be,

C=\frac{k\epsilon_{0}A}{A}

By E_{0} do you mean electric field or permitivity of free space?
 

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