The capacitance *C* in Equation 1.5 is determined by the geometry of the conductors. If we use Equation 1.1 and the definition that the *E* field is , it is easy to show that the energy stored in the capacitor is

where V is the volume of space containing the *E* field and ε is the dielectric constant.

Equation 1.6 is quite general and applies to an *E* field in a capacitor, in free space, or associated with a transmission line. In most cases the *E* field varies with position. An integration is needed to calculate the total *E* field energy in a volume of space.

Start Free Trial

No credit card required