## EE 333

**Homework Assignment 10 **

Due Oct. 31, 1997

- Problem 4.11 from the text.
- Problem 4.12 from the text. Note: The two spheres are both centered on
the origin.
- The field inside a one-dimensional semiconductor pn junction is

for 0 <= x <= x_{n}. Here q is the absolute value of the charge
of an electron, and N_{D} is the number of donor impurity atoms per
unit volume. Find the charge density.

- Find the electric field generated by the charge distribution

Find the symmetry in the field, and use Gauss's law to calculate **E**.
- The fair-weather electrostatic field above the earth's surface has the
empirical form

where a, b, c and d are positive constants and z is the height above the
surface.

- Determine the charge density p(z) as a function of height.
- Find the total charge within a vertical column from z = 0 to infinity with
cross-sectional area A.

*
Bill Rison,
<rison@ee.nmt.edu >
*