CAPACITANCE
DC Circuits
Example 1:
Find the capacitance of a capacitor that stores 8 C of charge at 4 V.
C
Q
V
C
8
4
C
2F
Example 2:
What is the charge taken on by a 5F capacitor at 2 volts?
Q
C V
Q
(5F) (2V)
Q
10C
Example 3:
What is the capacitance if the area of a two plate mica capacitor is 0.0050 m2 and
the separation between the plates is 0.04 m?
The dielectric constant for mica
is 7.
C
KA
d
(8.85 x 1012)
C
70.0050
0.04
(8.85 x 1012)
C
7.74 x 1012F
C
7.74 pF
Types of Capacitors
All commercial capacitors are named according to their dielectrics. The most common are air,
mica, paper, and ceramic capacitors, plus the electrolytic type. These types of capacitors are
compared in Table 1.
ES-03
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