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Edexcel Physics Unit 2 January 2012

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I saw a similar question of " how is a standing wave formed" in the rev guide.
key points are
-wave travels across string
-reflects at the end of the string
-incident and relected wave superpose to form standing wave
-antinodes are points constructive interference, nodes are points of constructive interference

Reply 61

britchick

I don't remember what I must have done for the A = P/F question but I remember getting exactly 15.
And for the curtain question I mentioned total internal reflection as well.

Reply 62

jake193

Horrible paper, wasn't it? I really hate the long QWC-based questions; if I wanted to write huge amounts of stuff I'd have taken English...

Reply 63

britchick

Original post by jake193

Horrible paper, wasn't it? I really hate the long QWC-based questions; if I wanted to write huge amounts of stuff I'd have taken English...

Yeah, I dropped English after AS for a REASON haha.

Reply 64

farhanyen

For last question, i wrote
-standing wave only formed when frequency is a multiple of fundamental frequency
-no standing wave is formed between multiples of fundamental frequency
-Because nL/2 has to = 2.0m(length of the string)
-Everytime, a new standing wave is formed it has 1 more antinode than before as n increase by 1
-because L is inversely proportional to f

BTW, can someone reply to my query abbt UMS grade boundaries
http://www.thestudentroom.co.uk/showthread.php?p=36009367#post36009367

Reply 65

Mtice

Paper went well, although I completely bluffed my way through the gold leaf question, as I missed most of the lessons on this unit last year, and I only only started revising for this resit the day before :/. I ran out of time, just after I'd done the ohms SI units question, so I definitely missed 10 marks... :frown:

The rest seemed pretty straightforward, and my answers seem to match the people's here.

I doubt I'll have an A, because of the last 10 marks, but I guess whatever I get, it's bound to be better than the E I got in the June paper (still not sure how, because when I counted the max. marks I could have on that paper, I only got to 20% :P).

Reply 66

yazdan

Original post by farhanyen

For the 2 mark curtain question, my answer was
-light totally internally reflects in the core of the optic fibre
-curtain is made of optic fibre
-light does not escape the optic fibre and is only released at the bottom of the curtain where optic fibre ends
-hence only the bottom of the curtain is bright

For the surface area of the solar panel question,
-power input=power output/efficency=500/15%=3333W
-A=P/F=3333/210=16m^2 (calculator value is 15.87)
How did you get15m^2.

Yh i think i did the same as you, hopefully its right

Reply 67

username714439

I completely blanked on the question with the V1 and V2. I just left it in the end. I completely made up my answer on the gold leaf question and reading what people have said on here I've got it completely wrong.

Other than that I think it was all right, I just hope that I got a better grade than I did the first time around, which isn't too difficult :smile:

, because I got a big fat E on that one.

Reply 68

britchick

Original post by Mtice

I doubt I'll have an A, because of the last 10 marks, but I guess whatever I get, it's bound to be better than the E I got in the June paper (still not sure how, because when I counted the max. marks I could have on that paper, I only got to 20% :P).

Original post by hannah_smiles

I just hope that I got a better grade than I did the first time around, which isn't too difficult :smile:

, because I got a big fat E on that one.

Hahaha I got an E in this paper in June too, so anything better I'll be really happy about.

Mark scheme anyone??

Original post by britchick

Mark scheme anyone??

Can you edit your first post and add an "Edexcel" tag for this topic?

Reply 71

britchick

Original post by Yorrap

Can you edit your first post and add an "Edexcel" tag for this topic?

How do I do that?

Reply 72

Yorrap

Original post by britchick

How do I do that?

When you edit your first post;

I am not sure whether this option is available for editting after a long time.

foq5w4.jpg32.8KB

Reply 73

britchick

Original post by Yorrap

When you edit your first post;

I am not sure whether this option is available for editting after a long time.

Wow thanks for the fantastic demonstration! Unfortunately I think you're right and it's probably too late to do that because no "label" part is available to edit. My apologies. I will do so though in the future.