What is the Line Integral of Magnetic Field in a Parallel-Plate Capacitor?

[Joe626]

Homework Statement

There is a current of 20 A in a resistor that is connected in series with a parallel-plate capacitor. The plates of the capacitor have an area of 0.80 m2, and no dielectric exists between the plates. Find the value of the line integral B ∙ dl , where the integration path C is a 15-cm-radius circle that lies in a plane that is parallel with the plates and is completely within the region
between them.

Homework Equations

b = muI/2rPI,

The Attempt at a Solution

i changed dl to 2PIdr and integrated. ended up with something that included ln(0). it just seemed wrong. any help is appreciated :)

 

[Spinnor]

See,

http://www.physics.upenn.edu/courses/gladney/phys151/lectures/lecture_temp.html

http://www.cramster.com/answers-mar-08/physics/ampre-maxwell-law-find-line-integral-loop-radiu_217689.aspx

Have you learned about displacement current yet?

 

[Joe626]

thanks i understand it now :)