General
1) A good fraction of students cannot solve simple circuits. You should have learned this in ECE35 (or equivalent) and used it in 45. Better learn circuit analysis now as circuits become harder and harder.
2) Grades tremendously suffered because a lot of students do sloppy work: messy write-ups leading to forgetting terms, decimals moving around, etc.
3) Many students still do not grasp that they are trying to be an engineer not a mathematician. Numbers are quoted with many digits and/or 23 micro A was quoted 0.000023 A (What would you say if the lab instructions says set the amplitude of the signal to 0.000023 V or you go and ask for a 10^-8 F capacitor?). Invariably these students made math mistakes carrying these extra digits around.

Problem 1. (OpAmp circuit) Majority of the class got the transfer function right. Very few got the input resistance right (and everyone had problem with input resistance in the midterm)!.

Problem 2. (Diode) This is similar to the problem 8 of the diode section of the lecture notes. Almost everyone draw the right circuit. A large number of students, however, could NOT solve those simple circuits.

Problem 5. (BJT amplifier Design). Most students got this right.

Problem 4. (passive low-pass filter Design). Most students got this right.

Problem 5. (DTL NOR Gates) Very few got this problem completely right. All sort of sloppy analyses!

Problem 6. (FET Amplifier). Majority of students got this problem right. However, a lot of points were lost because of math errors, etc.

Problem 7. (Darlington pair Amplifier). Half of the class got this right. Lots of "innovative" solutions such as finding BJTs in saturation although the problem clearly says that this is an amplifier!