# electrostatics homework 1

1. A flat circular disk of radius *a _{0}* has a uniform surface charge density The disk is surrounded by a sphere of radius

*R>a*. What is the flux through the surrounding sphere? (Hint: For a uniform surface charge, you can find the total charge by multiplying the charge density times the surface area.)

_{0}2. A flat circular disk of radius *b* with a surface charge density is surrounded by a sphere of radius *R*. The flat disk is located at the origin lying in the x-y plane, which means on the surface of the disk the angle is a constant 90 degrees with respect to the z-axis. What is the flux through the surrounding sphere? (Hint: For a non-uniform surface charge, you can find the total charge by taking the surface integral where varies over the surface of the disk. Choose an appropriate area element, *da,* in spherical coordinate system.

3. A cube of side *L* contains a plane slab of thickness *H<L* and surface area *L ^{2}*. The slab has a uniform volume charge density What is the total electric flux through the walls of the cube?

**From Fleisch Textbook:**

4. Problem 1.4: Do not find the electric flux, instead find the electric field both *inside* and *outside* the sphere.

5. Problem 1.9

6. Problem 1.10