Electrodynamics (I): Homework 10
Due: December 25, 2014
Exercises in Griffiths
6.3, 6.5, 6.7, 6.13 (hand-in 5%), 6.15 (hand-in 10%), 6.16, 6.18 (hand-in 10%), 6.21, 6.25,
6.28
Ex.1 hand-in 20%
(a) Suppose that the half space x < 0 is occupied by a medium with relative permeability
µ and the other half x > 0 is occupied by another medium with relative permeability µ0 . If
there is a line current I flowing along z direction at (x, y) = (a, 0), find the magnetic field
~ for all space points in terms of appropriate unit vectors in polar coordinates.
B
(b) A point magnetic dipole m
~ in vacuum is pointing toward to a plane surface of medium
with permeability µ. The distance between the dipole and the surface is d. Find the
magnetic field in the medium and outside the medium.
Ex.2 hand-in 10%
A infinitely long cylinder of radius a has uniform magnetization M perpendicular to its
axis. Let ẑ be the axis of the cylinder and x̂ be the direction of the magnetization. Find
~ and H
~ everywhere.
the magnetic fields B
1