1: Good, moderate difficulty capacitor problem. Basically tests that you know the basic relationship between the electric field and capacitance. The way it is asked makes it a little harder than a plug and chug.

2: Exam problem from last semester. Tests that you can calculate the capacitance of a parallel and a series combination of capacitors and relate to energy stored. Most students made a good shot at this one. Those that missed it either confused parallel and series formulas or forgot to say anything about the stored energy. I consider this low to low-moderate difficulty.

3: Conceptual. I’d love to see what answers would come out on the exam. Grading that would be great fun with a glass of scotch. It’s not a trick question … meant to be simple.

4: Moderate to difficult problem dealing with dielectrics.

5: Astrophysics 101 continued. See … this E&M stuff is so cool! Now we can estimate the temperature at the center of the sun! Difficult due to the scare/stun factor. Not too bad with the hints. Pretty mean without the hints.