Chapter 20 Gauss s law 第八章静电场 3)For the surfaces which is closed ◆S为封闭曲面 E 规定:取闭合面外法线方 向为正向。 We define of E s or of ds, to point E outward from the enclosed volume。 d s d④ el 0 Flux leaving the volume is positive. 几 d④<0 2 Whereas flux entering the volume is negativeChapter 20 Gauss’s Law 第八章静电场 规定：取闭合面外法线方 向为正向。We define of S or of dS, to point o u t w a r d f r o m t h e enclosed volume. E  , d 0 2 π  2  Φe2  , d 0 2 π  1  Φe1  S 为封闭曲面 dS1 d S 2   2 E2  1 E1  3) For the surfaces which is closed Flux leaving the volume is positive. Whereas flux entering the volume is negative