Presentation on theme: "Unit 1 Day 10 Electric Flux & Gausss Law Definition of Electric Flux Electric Flux thru a Closed Surface Gausss Law Derivation of Gausss Law from Coulombs."— Presentation transcript:
Unit 1 Day 10 Electric Flux & Gausss Law Definition of Electric Flux Electric Flux thru a Closed Surface Gausss Law Derivation of Gausss Law from Coulombs Law
Karl Friedrich Gauss 1777-1855 Developed a generalized and more elegant relationship between charge and the electric field (Coulombs Law)
Electric Flux The electric flux refers to the electric field lines that penetrate a given surface For a given uniform electric field E passing thru an area A, the electric flux is defined as:
Electric Flux θ is the angle between the E-Field and the line drawn normal to the surface The electric flux thru an area is proportional to the number of E-Field Lines passing thru the area
Electric Flux Thru a Closed Surface In general, an electric field is not uniform and the area is not flat ! Any area can be divided up into n number of small elements of surface area ΔA, sufficiently small to be considered flat and the E-field is rather invariant over this small area. Then:
Electric Flux Thru a Closed Surface In the limit as the sum becomes an integral Then a surface of any shape that completely encloses a volume of space is given by
Electric Flux Thru a Closed Surface A (+) - flux leaving the volume A (-) - flux entering the volume If every field line that enters a volume exits the volume, then: ; there is no net flux into or out of the closed surface The net flux will be non-zero only if the surface encloses a net charge The value of depends on the charge enclosed by the surface. This is Gausss Law !