Lecture_22_Part_2

Lecture_22_Part_2 - Flux through small area A n E flux"...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Flux through small area: A n E flux ! " ˆ ~ r Definition of electric flux on a surface: ! " # surface A n E ˆ r Electric Flux ! " # surface A n E ˆ r ! " dA n E ˆ r A d r ! " A d E r r electric flux on a closed surface = r E ! d r A " ˆ ! " " = # $ inside surface q A n E r ! " = # ˆ $ inside q dA n E r 2 4 1 r Q E !" = Gauss’s Law Gauss’s law: If we know the field distribution on closed surface we can tell what is inside. 1. Knowing E can conclude what is inside 2. Knowing charges inside can conclude what is E Can derive one from another Gauss’s law is more universal: works at relativistic speeds Dipoles: Electric field: ‘+’ and ‘–’ charges can be separated Magnetic field: no monopoles Suppose magnetic dipole consists of two magnetic monopoles, each producing a magnetic field similar to the electric field. One cannot separate them → total magnetic ‘charge’ is zero. ˆ ! " " = # $ inside surface q A n E r Gauss’s law for magnetism ˆ = ! " # surface A n B r ˆ = ! " # A n B r or Gauss’s Law for Magnetism All the currents in the universe contribute to B but only the ones inside the path result in nonzero path integral Ampere’s law is almost equivalent to the Biot-Savart law: but Ampere’s law is relativistically correct Ampère’s Law ! " = # path inside I l d B _ μ r r 1. Choose the closed path 2. Imagine surface (‘soap film’) over the path ! " l d B r r 3. Walk counterclockwise around the path adding up 4. Count upward currents as positive, inward going as negative !...
View Full Document

This note was uploaded on 04/02/2008 for the course PHYS 272 taught by Professor K during the Winter '07 term at Purdue.

Page1 / 22

Lecture_22_Part_2 - Flux through small area A n E flux"...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online