Exam I results

Well, the results are in. Apparently, you are more clever than anticipated :-)

The overall average was 80.75, with a standard deviation of 15.11, which I was very happy with. Four people answered all questions correctly, well done. Here is the histogram:



Keep in mind that one question is worth 5% (there were 20 questions), so it is somewhat expected that the 'spread' is a bit wide. An average of about 80 means missing only 4 questions. As you can see below, three questions in particular were on average more difficult:


Questions 4, 11, and 12 were most difficult, and I find this somewhat reasonable: question 4 required a subtle application of Gauss' law, and with question 12 it was easy to either misinterpret the question or misapply the power formula. I expected both of these to be harder.

Question 16, another difficult one on average, was basically dimensional analysis in disguise, but nonetheless quite tricky. Question 18 is probably lower due to our covering RC circuits very quickly. Again, I am not surprised that these two seemed more difficult.

Question 11 was, you may now realize, distilled from problem set 4 question 9. It was a difficult question, but one you had the solution to in advance. I did expect it to have a lower average, perhaps not quite as low as it was though.

One very good point: question 17 was right off of the last quiz. On the quiz, only 13% of you answered correctly, compared to 92% on the exam. This is what we like to see!

Anyway: early next week exam solutions will be posted, along with analysis comparing each exam question to a previous similar question from the problem sets or quizzes.