4.6.4 Power Dissipation in a Real Dielectric

Hence, a.c. conductivity can be expressed as

(4.70)

If σ_dc is very small, then

(4.71)

Now, the time average power loss can be expressed as

		(4.72)

(4.73)

OR

(4.74)

Hence, if C₀ =(ε₀A/d), C₀ = (V₀/d) and V = A.d, the dissipated power density in a dielectric would be

One can now see that for static or d.c. fields, ω = 0, i.e.

(4.75)

and hence,

(4.76)

which is the standard equation for power dissipation in a material under dc fields.