E6chalsoln - Phy sics 7B WS E6 Challenge Solution(rev 1.0...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Physics 7B WS E6 Challenge Solution (rev. 1.0) Page 1 E-6 Challenge Problem Force on a Dielectric in a Cylindrical Capacitor Consider a cylindrical capacitor with inner radius a, outer radius b, and length l (ignore any fringing effects). a) What is the capacitance of this capacitor? To find the capacitance, put a charge +q on the inner cylinder and a charge -q on the outer cylinder. We will assume that the length, l , is much bigger than a or b, so we can ignore fringing effects when we find the electric field. To find the electric field, assume that the cylinders are infinitely long with a charge per unit length λ = ± q/ l . Use a gaussian cylinder of length l and radius r (a < r < b). By the cylindrical symmetry, the electric field only depends on the radius r and only points in the radial direction. Therefore, the flux through the cylinder is Φ = 2 π r l E(r). The enclosed charge is just λ l = q, so r E ( r ) = q 2 "# 0 r l ! r To find the potential difference between the cylinders, integrate the electric field over the path
Image of page 1

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

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern