{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

test2-S10

# test2-S10 - b Find the net force between the sphere and the...

This preview shows page 1. Sign up to view the full content.

Physics 318 R.G. Palmer Electromagnetism 4/5/10 Test 2 1. a. There is a local magnetic field at a magnetic dipole, H local , which is not the same macroscopic field H (like the electric field). In a uniform magnetization M , find H local from H and M . Write down your steps and assumptions. b. A magnetic dipole m is stable if it is the same direction of the local magnetic field. Magnets are generally unstable unless they have use a “finder” (a magnetic material in the gap). Show this for (i) an “anchor ring” (a torus with a gap) and (ii) a bar magnet. 2. Outside a grounded conducting sphere of radius a lies a uniformly charged ring of radius b with total charge q . The sphere lies on the axis of the ring, and the centers of the ring and sphere are a distance d apart. If c = b 2 + d 2 , then c > a since the ring is outside the sphere. a. Find the electrostatic potential everywhere outside the sphere.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: b. Find the net force between the sphere and the ring. You should be able to write the magnitude of this in the form F ∝ q 2 ∞ X l =0 A l P l (cos α ) P l +1 (cos α ) where cos α = d/c and A l depends on the geometrical parameters, by using some recurrence rela-tions. 3. A closed annular tube consists of the region a ≤ ρ ≤ b , 0 ≤ z ≤ c in cylindrical coordinates. The curved surfaces ( ρ = a and ρ = b ) and the bottom ( z = 0) surface are held at 0 potential, while the top ( z = c ) surface is held at potential V . Find an expansion for the potential inside the tube. Notes: For full credit you need to evaluate the V integral, by using a recurrence relation. You do not need to evaluate the normalization integral (although it can be done)....
View Full Document

{[ snackBarMessage ]}

### What students are saying

• 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.

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

• 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.

Dana University of Pennsylvania ‘17, Course Hero Intern

• 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.

Jill Tulane University ‘16, Course Hero Intern