Physics Teachers Forum

how much detail do we need to teach on transistors? Do the students need to understand how they work, or just what they are used for, the history behind it and their impact?

Rachel,
I hope other school teachers can give you a definite answer to your questions, but having just coauthored year 11 and 12 books I can give my interpretation of the syllabus and the emphasis I used in the books.

A short answer to your question would be that students should know a bit about each of the points that you mentioned, even though the syllabus points don't specifically say "describe how transistors work".

Other teachers have found it unsatisfying to students when an explanation of how they work is not given. Saying that they are some kind of switch, naturally leads many top students to wonder about the mechanism since they have just learned about P and N junctions and can see from diagrams that transistors are made of these.

It doesn't make a great deal of sense dwelling on an old technology such as cathode ray tubes and how they work and giving scant regard to transistors, which is a contemporary technology.

The syllabus does ask to give a comparison between thermionic and semiconductor devices. To make the syllabus relevant to what they see today inside their computer you may need to talk about the integrated circuit and therefore talk about the transistors that makes up these circuits. Certainly history and impact are specified in the syllabus, but it would not really be physics without mentioning how they work :-) even though the syllabus does not say it.

My own writing about this addressed all of the points that you mentioned: Their use, history, how they work and impact.

Hi Rachel and Joe,

The simple way I answer questions like this for myself is that I make sure I have taught things to the depth covered in the most popular HSC physics texts.

Theoretically the HSC examiners can only ask questions on the syllabus dot points but occasionally there is a question that clearly asks about something covered in one of the popular texts but is not actually directly covered by the dot points. So as I have said, the safest thing I have found to do is to cover the material in the popular texts even if it is a little outside the dot points.

I agree with Joe that kids will naturally want to know how transistors work. I use a few diagrams and they write some notes around them highlighting the parts and how they work together.

Cheers,
Jeff