1 Four closed surfaces, S₁ through S4, together with the charges -2Q, Q, and -Q are sketched in the figure below. (The colored lines are the intersections of the surfaces with the page.) Find the electric flux through each surface. (Use the following as necessary: ε and Q.) S1 S2 S3 S4 || || -2Q +Q Sq

A long cylinder of copper of radius 3 cm is charged so that it has a uniform charge per unit length on its surface of 3 C/m. (a) Find the electric field inside and outside the cylinder. (b) Draw electric field lines in a plane perpendicular to the rod.

In which of the following contexts ran Gausss law not be readily applied to find the electric field? (a) near a long, uniformly charged wire (b) above a large, uniformly charged plane (c) inside a uniformly charged ball (d) outside a uniformly charged sphere (e) Gausss law can be readily applied to find the electric field in all these contexts.

A very long line of charge with a linear charge density, , is parallel to another very long line of charge with a linear charge density, 2. Both lines are parallel to the y-axis, and are the same distance r from the y-axis, where the first wire is to the left of the origin and the second is to the right. Use Gausss law and the principle of superposition to find an expression for the magnitude of the electric field at the origin.