MITx 6.002x: post mortem 1

Now that the final exam has finished and the only thing that appears to be happening in the 6.002x forum is a lot of bickering about certificates, I thought I’d write a couple of posts to finish my journey off. This first post will simply look at how I did in the final exam. In the second post, I’ll reflect more generally on the experience and document what I thought was good / bad / indifferent about 6.002x as a whole.

The final exam had 10 questions, each with a number of different parts (1 mark per part), with 47 marks available in total. As I’d written in an earlier post, I needed to score 2/47 to ensure a pass and 34/47 to obtain an ‘A’ grade. In the end, I finished with 32/47 – a comfortable grade ‘B’ pass. Most of the questions I had difficulties with covered material from the first half of the course rather than the second half. I put that down to the second half of the course having become a little more practical in focus – in short, it contained the more interesting material!

Question by question:

1. Strain (5/5) – a nice simple resistive circuit problem to solve just to get into the swing of things.

2. Logic circuit (7/7) – another “gimme” as far as I was concerned. If I had a single criticism of the course content (and it’s not really the course’s fault, more my own expectations of it when I started) it’s that there wasn’t nearly enough digital in it. But at least there was a question on what little there was on the topic!

3. Switched capacitor (5/5) – straightforward stuff involving the calculation of a couple of different time constants. It took me two attempts to get all of the parts correct, as I hadn’t originally spotted that I’d need to re-calculate the time constant when the circuit was switched through the second capacitor … durr.

4. Bipolar Junction Transistor (0/9) – this is where I lost any chance of an ‘A’. It wasn’t really anything to do with a BJT – more a large signal analysis of a couple of voltage sources and a voltage controlled current source, followed by a small signal analysis. I got hopelessly lost and didn’t have the time to go back to first principles to sort it out. I still don’t think that it was a difficult or unfair question – I simply messed it up. Oh well.

5. Op amp with an RL filter (2/3) – straightforward, but I still manged to get the final part wrong as I’d missed out the RS resistor in the algebraic expression – I must learn to write more clearly.

6. Op amp FET (0/2) – I’ve no idea even now about how to solve this one! Hopefully the course team will publish a worked solution at a later date.

7. Trapping noise (3/4) – I have no idea what the part I missed out was asking for – otherwise, it wasn’t too bad a question.

8. Increasing Q (6/6) – no real difficulties with this one, apart from inexplicably multiplying one frequency by 2pi and not the other when working out the bandwidth on my first submission. I sorted that mistake out second time around.

9. Scope probe (4/4) – a repeat of one of the homework questions from a few weeks ago, just with slightly different values this time. Straightforward therefore.

10. Triode amplifier (0/2) – the course team weren’t joking when they said it was ” intended to stretch you beyond the material that we explicitly taught in this class” and “do not work on it until you have finished with the other problems.” More of a “WTF” moment than a “Aha” moment I think.

So 68% on the final exam; 86% overall. A very solid B and I’m pleased that I managed to stick with the course all of the way through.