Electric Field on the Axis of a Uniformly Charged Disk
The theme of today's class is the binomial theorem. First, each of the expressions for E was calculated at an arbitrary distance from the charge distribution; then the expression was considered in the limit far away from each charge distribution. The charged disk was seen to behave as a point charge far away. The dipole was found to have an E field which fell off as r-3, rather than r-2 as for the point charge.
The binomial theorem plays a big role in allowing us to check the limiting behavior of expressions that we derive.
Another Dipole Example: Quiz 3 extension, Fall'97 -- not for the faint hearted...
Last updated March 10, 1998.
Copyright George Watson, Univ. of Delaware, 1997.