Student "edition" found at {csi dot journalspace dot com}.

Maybe I shouldn't have started this blog now, not with everything that's been going on.

On the third day of the seventh week of classes I had the third experiment in Electricity and Magnetism lab.

During the quiz at the start of the class, one student was surprised because she didn’t even know there was a quiz, since she missed the first two during the previous meetings and none of them have told her about it.

This, I told them beforehand, is just the first part of one “long” experiment in their manual, Resistors in Series and Parallel. I separated this experiment to compensate for having removed one of the other basic experiments in the manual for which we still have not gotten proper equipment – Electric Fields.

There is a place in the system where I could get their old and unused materials (so old that it still bears the “college” label instead of “university) and which, from my previous years of experience, are dangerous enough that in spite of several repeated warnings against touching the probes when the current is on, can send the female students to tears when they forget, and in one memorable instance has even sent a spark to appear on the earring of one male student.

I just spruced up the procedure so that instead of having to make one circuit for this first part with three resistors, they had to make three more circuits with combinations by two of the three resistors given.

Since we did not have any decade resistance boxes and we don’t know if they can still be obtained anywhere, I also had to assign the closest values to the resistors we already have. This was so they could practice reading the color codes of resistors also.

Some tried to cheat by checking the values of the resistors on their multi-testers, but they forgot to remove them from the circuit before reading, so they didn’t know they were actually getting the total resistance of all the connections.

Another form of cheating they tried (or talked about) was reading only one current in series and assigning it to the rest, since current is supposed to be equal for all parts of the series circuit anyway.

I reminded them that they are already assuming the theory works, when the point of performing the experiment is to prove the theory.

Because of this shortcutting, these groups (merged because of the lack of probes for the DC voltage generator we haven’t found yet) forgot to measure the total voltage and relied on the computed voltage instead. That’s one less table for them, and larger error resulting in comparison with a different quantity than they were supposed to.

And I’m pulling the plug on session 639. For now, class dismissed.