AQA A Physics Unit 4 24th Jan 2012

Yeah, the bungee questions weren't pleasant. It asked about where the stress was greatest (I said top as Tension acts there), and at the greatest amplitude, as educated guesses.

The Last question (6 marker) and the 2 mark question after screwed me right over. I'd never seen a set up like it.

I know why the EMF was induced and mentioned lenz's law, but didn't see how it was relevant to moving the ring, so mentioned F=BIL from the iron rod must be equal to the weight of the ring.

One of my friends's said something about the rod having a natural frequency (lambda/2 is the length of the rod). Angry that it's not in the textbook, and was not taught this.

For the 2 marker I said ring moves up, because dphi/dt was increased, but that was a guess and probably wrong. Could be looking at low-mid 50's for this paper, hope I don't have to resit, as I've put so much work in to Physics this year, and need an A for uni.

haha just kidding

Doesn't matter as long as you showed correction direction and that it was straight + curved around the edge.

for the electric field question i drew it wrong so i crossed the whole thing out and drew it next to where the diagram was and labelled the +3 top plate and the +1 bottom plate, will they accept that?

I don't really understand the point of it though. They include like 10 marks worth of questions on random stuff, but totally leave out Momentum and Circular motion, which are actually on the syllabus and people have revised them for nothing.

I did and got the question paper shall i post them up?

yeah but i did it wrong and cant remeber how many marks it was so would be interested to know what i lost

6800ohms anyone? Got 15ms too?

I agree lol I never saw the point of A2 modules being synoptic.. waste of time revising for things that don't come up and I'm sure the OCR Biologists or any ocr exam taker will agree.



And for the plate fields question, one mark for direction, one mark for straight lines and one mark for curved aroudn the edge I believe.




should be that, can someone confirm what direction it was? I put the exact same as the diagram above, charge for top have was +3.0C, bottom plate with +1.0C, I think direction should be bottom to up

I agree lol I never saw the point of A2 modules being synoptic.. waste of time revising for things that don't come up and I'm sure the OCR Biologists or any ocr exam taker will agree.



And for the plate fields question, one mark for direction, one mark for straight lines and one mark for curved aroudn the edge I believe.




should be that, can someone confirm what direction it was? I put the exact same as the diagram above, charge for top have was +3.0C, bottom plate with +1.0C, I think direction should be bottom to up

.. I did, but others think different =/

i think it was a 2 mark question

Top to bottom is right i think because it's the direction that unit positive charge would follow

What did people get for the lamps question?
I got 5 but my friend got 3 as he said you have to use current over root 2 as its AC... is that right??

What did anyone put for the reasons why the bungee was not in SHM above a point.

Was it to do with acceleration not being proportional to displacement?

What did anyone put for the reasons why the bungee was not in SHM above a point.

Was it to do with acceleration not being proportional to displacement?

What did people get for the lamps question?
I got 5 but my friend got 3 as he said you have to use current over root 2 as its AC... is that right??