Читать книгу Antennas - Yi Huang - Страница 28

(1.32)

This is the electrostatic application of Gauss's generalized theorem, giving the equivalence relation between any flux, e.g. of liquids, electric or gravitational, flowing out of any closed surface and the result of inner sources and sinks, such as electric charges or masses enclosed within the closed surface. As a result, it is not possible for electric fields to form a closed loop. Since D = εE, it is also clear that charges (ρ) can generate electric fields, i.e. E ≠ 0.