Re: Controversial Exam Questions (WAS: R = V/I ?)

[Leigh Palmer <palmer@SFU.CA>]

> Mark Sylvester wrote:
> > This thread has been put into a certain wry perspective for me by a
> > question on paper 2 of the IB examination, which my students did on Monday
> > and I got to see today:
> >
> > There is a plot of V vs I for a filament lamp, and in one line, for one
> > mark they had to "State whether or not the filament of the lamp obeys Ohm's
> > law"!
>
> Ive tutored a lot students - and IB has been a large fraction.  One
> constant frustration is old exams or practice questions that they want
> to go over which have more than one "right" answer in multiple choice
> form.  When its their own teacher's old exam I explain the debate and
> tell them to ask their teacher which way (s)he is intending it, but when
> its a widely distributed exam like IB I have to tell them to flip a coin
> and hope for the best.

I hope you aren't suggesting that this question is ill posed. From what
you've been writing it is clear that you think the correct answer is
that the filament does not obey Ohm's law. Asked in that way it would
be impossible to reasonably argue otherwise.

Leigh