1. Consider an imaginary closed surface in the shape of a tuna fish can
Consider an imaginary closed surface in the shape of a tuna fish can. A person establishes that the net outward flux through the surface is greater than zero. What can you say about the net charge inside the closed surface?
a) It is less than zero.
b) It is greater than zero.
c) It is zero.

2. (Demo using board of nails and wire loop held with plane of loop parallel to board at each of 2 locations. The nails represent electric field lines.) In which case is the electric flux through the loop greater?
a) In the first case.
b) In the second case.
c) Neither.

3. (Demo using board of nails and wire loop held with plane of loop perpendicular to board at each of 2 locations.) In which case is the electric flux through the loop greater?
a) In the first case.
b) In the second case.
c) Neither.

4. (Demo. Put model of positive point charge in box
(Demo. Put model of positive point charge in box.) What can you say about the net flux through the box for the actual case that is represented by the model?
a) It is less than zero.
b) It is greater than zero.
c) It is zero.

5. (Demo. Put model of positive point charge in box
(Demo. Put model of positive point charge in box.) What can you say about the net charge in the box for the actual case that is represented by the model?
a) It is negative.
b) It is positive.
c) It is zero.

6. What do the differential and the circle on the integral sign tell you about the integral ?
a) That the integral is over a closed surface.
b) That the integral is about a closed loop.
c) That the integral is about a circle.
d) None of the above.

7. Given a specified unsymmetrical charge distribution and an imaginary closed surface enclosing all or a specified part of the charge distribution and asked to find the net outward electric flux through the surface, which is the better way to proceed?
a) Find the electric field at each point on the surface, and integrate
b) Calculate the total amount of charge enclosed by the imaginary surface and divide the result by eo.
c) Neither. The net electric flux is zero.