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Figure 1.1 The most common type of
capacitor consists, in principle, of two conducting plates parallel to
each other and separated by a small space combatively with the linear
dimensions of the plates (see Fig. 1.1).

Practically the entire field of such a capacitor is localized in the
area between the plates, as shown. There is a slight "fringing" of the
field at its outer boundary (bending outward of the field lines near the

edges), but if the plates are sufficiently close, this may be omitted.
The field between the plates is then uniform, and the charges on the
plates are uniformly distributed over their opposing surfaces. This
arrangement is known as a parallel-plate capacitor or condenser.

The electrocapicity of such a condenser is equal to

 S
C  0 (1.2)
d

where d is the distance between the plates, S is the area of each
plate,  is dielectric permitivity of a medium between the parallel-

plates of a condenser,  - electric constant (  , 8 85 10  12 F ).
0 0 m
The capacitance of a parallel capacitor is equal to

Figure 1.2.

Figure 1.3.

C  C  C ....  C (1.3)
1 2 n

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