Gawds knows m8 its what I did my lecture on
which I might add was choosen by dropping a book and doing the subject the page fell open on. The examiner got the instructor to choose the subject a couple of days before the flight test using this method.
I think the object of the exercise is not par say to lecture on the the PPL subject. Its to show that you can construct a lecture and give it. The subject matter dosn't really matter.
Personally I didn't mind the subject I just downloaded the lecture plan from the 2nd year Mech Eng Aero course and printed the hand out. Chopped most of the maths out and went into lecturing mode.
MJ