1 / 8

Fields and Waves

Fields and Waves. Lesson 5.1. TIME-VARYING FIELDS. Displacement Current. Ampere’s Law. Time varying field. Static field. Integral Form of Ampere’s Law for time varying fields. Displacement current I d. I C - Conduction Current [A].

tristar
Download Presentation

Fields and Waves

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fields and Waves Lesson 5.1 TIME-VARYING FIELDS Lale T. Ergene

  2. Displacement Current Ampere’s Law Time varying field Static field Integral Form of Ampere’s Law for time varying fields Displacement current Id IC- Conduction Current [A] – Electric Flux Density (Electric Displacement) [in C/unit area] - Current Density (in A/unit area)

  3. Displacement Current Total current Displacement current density • Connection between electric and magnetic fields under time varying conditions

  4. Example: Parallel Plate Capacitor Imaginary surface S1 ++++++++++++++++++++++++++++ + Imaginary surface S2 E-Field - - - - - - - - - - - - - - - - - - - - - - - - - - - - S1=cross section of the wire S2=cross section of the capacitor I1c, I1d : conduction and displacement currents in the wire I2c, I2d : conduction and displacement currents through the capacior

  5. Example: Parallel Plate Capacitor In a perfect conductor I1d=0 From the circuit theory: Total current in the wire:

  6. Example: Parallel Plate Capacitor Electrical charges can’t move physically through a perfect dielectric medium (zero conductivity) I2c=0 no conduction between the plates The electric field between the capacitors d :spacing between the plates

  7. Example : Parallel Plate Capacitor The displacement current I2d • Displacement current doesn’t carry real charge, but behaves like a real current • if wire has a finite conductivity σ then Do Problem 1

  8. Boundary Conditions • Boundary conditions derived for electrostatics and magnetostatics • remain valid for time-varying fields: dielectric-dielectric boundary dielectric-conductor boundary

More Related