A 4 page entry

Seed Question:Consider a solid metallic cube. Imagine that a charge–Q is somehow released in the center of the cube. Assume –Q is in contact with the conductor. What will happen? Explain fully!


1. Find the electric field just above the surface of a conducting sphere with radius R and charge +Q. Apply Gauss’ Law.

2. How does this result compare with what you would get applying Gauss’ Law to a small region near the conducting sphere’s surface?Draw the electric lines of force. Sketch a small “pill bottle” such that the electric field will be either parallel or perpendicular to the walls of your “G-Surf.”

3. A thick walled neutral, hollow, conducting sphere surrounds a fixed charge +Q at its center.

4. Find the electric field a distance r above an infinite line of charge with linear charge density lambda +.

5. Find the electric field outside and between these infinite sheets.Hint: You will need 2 Gaussian surfaces…Which one should you use first?

6. Last one. A hollow conducting sphere with net charge +3Q, surrounds a charge –Q, located at its center.
A) Find the electric field vector at points P1, P2 and P3.

B) Find the charge on the inner surface of the sphere.Show your G-surf!

C) Find the charge on the outer surface of the sphere. All you need is addition for this one…

Big Idea:Applying Gauss’ Law:

Sketch Faraday’s lines of force first, then choose your Gaussian surface to take advantage of the symmetry of the field: choose your surface so that is either // or  to . If is // to it needs to be constant!


Note that = 0 inside anyconducting material in the static case. If it wasn’t, charge would flow (in about 10-18 s) until it was! may or may not be 0 inside a hollow region of a conductor.

Discussion: ?