04-10-2010, 08:13 PM
(03-10-2010, 07:45 AM)Peter Wrote: Am I alone in wondering why the ballast resistance give in this years question is again given the wrong units like last year? ....
I'm all for challenging students, but on an item where most people tend to struggle on the concept, giving them a duff steer in the specification is a bit off in my view. I wonder whether it was deliberate or a bad error. Throw into the mix that, as far as I can see, when you do the calcs properly, you end up with a surprisingly long TC.
Some months ago I did speak to the examiner responsible for setting the 2009 question and was assured that not only was he "not being given the opportunity of fouling it up again this year", but that the question was being "triple checked". Ummm.
I suppose it shows we are all human, but really I don't think it is good enough- they would rightly criticise a candidate for making an error in their units and in my view this should not have been allowed to get through. However I subscribe to the view "never attriibute to malice that which can adequately be explained by incompetence", so I think it most unlikely to be a deliberate ploy- that I would regard as unfair.
It seems as if there is a broad consensus regarding the length- although a negative shunt value is indicative of having made some wrong assumption or arithmetical error!
PJW