OCR B G491, 17th May 2012 Morning.

but i thought you had to find the resistance not the internal resistance?

I used the formula: E= I(R+r)

Yes but in fomula book its V=E-Ir but i rearranged to get R

60 minutes is not long enough for that exam.

Everyone at my school found the exam really really hard :/ it wasn't a very good exam :/ but now I'm worried just need to well in the next one now, but I think the first exam is harder than the first anyway :/ well I hope it is

I hope everyone does bad so grade boundaries are low...

60 minutes is not long enough for that exam.

I found this exam okayish, but probably made a few stupid mistakes! Not many people are posting answers so here's what I got from what I can remember..

The materials question about linking the boxes I said that strain = force per unit area, hard = difficult to indent, tough = needs alot of energy to break and stiff was the other definition can't remember what it said now!
The question about the lens and the magnification, I got magnification = v/u and 0.001.
When it asked about the number of sig figs I said 4, and the % uncertainty I got 0.098% so 0.01%.
The bandwidth question I got something like 4.47x10^8? Though that seems very large so is probably wrong.
The polymer question, I said that the atoms were covalently bonded and rotational so could be stretched elastically and after reaching the elastic limit 'necking' occured.
The question about polarised light I simply said that polarised light only oscillates in one direction? Not sure how that added up to 3 marks though!
The very last question about the 3D glasses I ran out of time for and just wrote 'the orientation of the polarised filters changes'

Someone please say they got similiar to this!

I found this exam okayish, but probably made a few stupid mistakes! Not many people are posting answers so here's what I got from what I can remember..

The materials question about linking the boxes I said that strain = force per unit area, hard = difficult to indent, tough = needs alot of energy to break and stiff was the other definition can't remember what it said now!
The question about the lens and the magnification, I got magnification = v/u and 0.001.
When it asked about the number of sig figs I said 4, and the % uncertainty I got 0.098% so 0.01%.
The bandwidth question I got something like 4.47x10^8? Though that seems very large so is probably wrong.
The polymer question, I said that the atoms were covalently bonded and rotational so could be stretched elastically and after reaching the elastic limit 'necking' occured.
The question about polarised light I simply said that polarised light only oscillates in one direction? Not sure how that added up to 3 marks though!
The very last question about the 3D glasses I ran out of time for and just wrote 'the orientation of the polarised filters changes'

Someone please say they got similiar to this!

I got the same for most of this except the bandwidth which i was really confused about...
for the polymer question i said that after the elastic limit the bonds stretched out so they were in a straight line rather than bunched up and then at the breaking sttress, the stress was great enough to break one of the bonds....
for the glasses question i talked about how when yu have two polarising filters at right angles, no light is allowed through, and how when there is only one some light is let through

I said the same as you for the polymer question and the magnification. what did you get for the power of the lens?

I said the same as you for the polymer question and the magnification. what did you get for the power of the lens?