[WhiteAndNerdy]

Anything in particular you are nervous about? I personally cannot stand the electricity questions!

[Jake011268]

Electricity questions rack my brains, im just hoping its nothing like the Maths exams ive just sat and they go way off :/

[Turbintajj]

I don't like the particle stuff and feyman diagrams but I'm ok with electricity questions

[PatroclusFTW]

Yeah I don't like those electricity questions either.... rest of the calculations are ok, but never keen on Pair production and annihilation longer questions And "how science works" random 2 markers- I HATE those.
:P

[humziie]

oh god, who did c2 today?? !!! bloodddy killer
can anyone tell me wat they got for the last gradient question?

[coolstorybrother]

could someone explain jan 12 6 bii please? What is it about components in parallel that means we can tell what the current should be only given the voltage should be the same across both....

[Matt_Potential]

How did you get hold of Jan 2012 paper? If you can send me a copy of the paper, I'd be happy to help you with the question if i can

[WhiteAndNerdy]

(Original post by Turbintajj)
I don't like the particle stuff and feyman diagrams but I'm ok with electricity questions

Yeah I hate those Feynman diagrams too haha - and those pointless 6 mark questions!

[SexyJinny]

Paper and mark scheme attached

[SexyJinny]

(Original post by coolstorybrother)
could someone explain jan 12 6 bii please? What is it about components in parallel that means we can tell what the current should be only given the voltage should be the same across both....

You know from part a that the current through X is 3A, and the current through Y is 0.44A, so the current through the parallel branch is going to be the total current so 0.44+3 = 3.44A.

Because current splits in parallel but, components dont use up current(i.e total current in = total current out), which is why total current through the parallel combinations = the current through R1, as they effectively are in series

[ChristinaLee]

Did anyone find the June2011 past paper hard?

[FK_]

Does anyonee have the physics unit specimen paper? Cant seem to findit. Would be much appreciated!

[Ben_055]

Come on everyone! We can do this!!

[Ben_055]

Just looked at your Jan 12, and it looks like you guys are doing a completely different paper to me tomorrow.

[tictac103]

i HATE the electricity Q's i seriously need a confidence boost i feel like i know nothing!!

[SoIWannaBeADoctor]

What do you all think is going to come up?

I personally cant revise at all due to the KILLER headache i got from c2 maths today

[SoIWannaBeADoctor]

and I KNOW I HATE ELECTRICITY

[laurenb11]

(Original post by ChristinaLee)
Did anyone find the June2011 past paper hard?

I found the 6 mark question quite hard about bombarding electrons and line spectra! Didn't write enough for the 6 marks :/

[jamesp1235]

Can some one tell me what type of decayed their are and how to conserve baryon and lepton number

[SexyJinny]

(Original post by jamesp1235)
Can some one tell me what type of decayed their are and how to conserve baryon and lepton number

For decays there is only through weak interaction, so i think the ones that we need to know is:

N -> P + e- + AntiVe
P -> N + e+ + Ve

Basically, the ones that are baryons (proton, neutron, all with 3 quarks) have a baryon number of +1 and the anti baryons(anti-proton, anti-neutron, 3 anti-quarks) have a baryon number of -1.
So just assign the values +1 and -1 to each and if the baryon number before is same as the baryon number after it is conserved

Same applies for lepton number but you have Muon numbers and Electron numbers.