Ch 16 Capacitance


The capacitance C of a capacitor is defined as the ration of the magnitude of the charge on one plate to the potential difference between the conducting plates.

C = Q/V

Capacitance = Charge stored / potential difference
..

C = Eo A/d

Capacitance = (Epsilon zero X area) / (separation)
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Energy Stored in capacitor

U = (Q^2)/2C = 1/2 QV = 1/2 CV^2


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permittivity E = kEo where k is the dielectric constant

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PLEASE check out Hyperphysics Capacitance web resources- excellent stuff!

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The Hyperphysics concept map for capacitors links you to a RICH set of mathematically explained resources.
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Capacitors in combination


Variable
Series......................................
.............
Parallel..............................
Equivalent capacitance
1/Ceq = 1/C1 + 1/C2 + 1/C3 +...

Ceq = C1 + C2 + C3 + ...
Equivalent charge
Qeq = Q1 = Q2 = Q3 = ...

Qeq + Q1 + Q2 + Q3 + ...
Equivalent voltage
Veq = V1 + V2 + V3 + ...

Veq = V1 = V2 = V3 = ...