AQA MOd 4 IMPOSSIBLE
Physics and electronics discussion, revision, exam and homework help.
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AQA mod4 impossible-how did it go?help i hate thi smodule i spent 3 days reivsing it and doing little else, tried the jan 03 paper and for everyquestion my responce is EH?!? Non of th eformulae seem to help, the questiosn just don't match what I have learnt they are close-ish but still impossibly hard, i am really worried, anyone else panicing insane amounts over this module, or got any quick fix reivsion tips , the exam is on thursday and i have to revise mod9 as well before then
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Doing the same Paper on thursday, the problem is your trying to look for a quick fix to every question. In AS you can learn the crap and then real it off for the answers, this time you need to learn the crap then apply it to the question.
What I always do is when I see the word 'diffraction grating' for example is write down the formula and you can usually work from there. The first section is multiple choice, just do a few more past papers and check your answers against the mark scheme and it starts to pop into place.
Just remember if you get stuck on a question, look in your book, still stuck look at the answers, then understand the answer!
You know you can get all the past papers and mark schemes from here?
Here!
Oh and I don't promise any of the above works and I'll probably gonna fail anyway
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It is a rather tricky module, but as dogberry said, practise the multiple choice! At first i was a bit confused by most but after a while you learn what they are asking.
Eg there are normally one or two along the lines of "A force between two point charges is F, distance r. if distance increased to 3r what is the force?"
Look at the equation for force, F=-GM/r². -GM is constant for the two forces so remove it, swap r with 3r so you get 1/9r² so F/9 as the answer!
Im not looking forward to it either though, i know the maths its the theory i cant do! -
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I have some of the theory down in my head, I keep forgetting the formulae. You are spot on about application,dogberry, and I have been trying to learn everythign before I try past papers, but Am going to rush through them all tonight. I dislike the multiple choice questions because they tend to ask for comparisons rather than answers but im sure i can get used to it. A lot of the questions don't seem to give me enough info, then when you look at mark scheme they do something I woudl never have thought of, often dragging in synoptic bits from previous mods.
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Yeh noticed that 2, full of little tricks. Had noticed that the paper does seem to give plenty of time so should be able to sit and stare at any funny ones, but that doesn't mean you'll work 'em out, just have time to suffer
Good Luck! Oh and don't do too much tonight, as soon as one bit goes in another falls out the otherside. -
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yes ive also found that, im just going over past papers, making sure i know most of the answers, but if i don't know it now, there's no point in cramming!i'll just end up over stressing, im nervous alreadyGood Luck! Oh and don't do too much tonight, as soon as one bit goes in another falls out the otherside
think i'll be alright though, GOOD LUCK EVERYONE!
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You have multiple choice? I cannot belive how much better option A is compering with option B in AQA Physic :/. Easy to guess my school does option B. Nevertheless good luck, particulary for Laffo (improving from D to A under pressure of an offer must be realy hard work).
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I think i had the right sor tof idea for most of the questions but phrased thnings poorly and missed a few key words so will lose lots of marks. THe multiple choice was alright except for a few "wtf" questions.However parts of the written section had me so confused I was guessing my way through everything.I was 1 mark off a C last time i took it, hoping to get a B this time but I think i can just about cope with a decent C cause i have got good coursework and AS results. Took mod9 as well today which went VERY BADLY so bring on synoptic so I can boost my marks back up!
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Found the multiple choice ok, but the written part I found pretty hard and was short of time at the end. Is it supposed to be 50/50 multiple choice/written? I did the multiple choice in about 30 mins but still nearly ran out of time on the written part.
On the multiple choice what did you get for the one with the -4 and +16 charges with 120mm gap question? I think I put 40mm.
The paper seemed harder overall than the practice papers I'd done. Hope it's not just me then hopefully it'll be scaled up! A medium C grade is enough for me this year though so not too stressed just yet! Will see after synoptic though. -
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I coudlnt figure out the 4/16 charges question I just guessed it and picked the lowest value. How did you do with all that ratio of neptune,the earth and the sun radii/distace/orbit etc. THat was HARD couldnt prove the T prop. R found orbit of planet to be around 400days(or was is 200 it was one side of 300 lol) but coudlnt do the ratio of distance from sun ended up with 9000^2/356^2 x k
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Yeah, the answer was 40mm for the charges. It was potential so the force due to each charge was inversely propertional to the distance between them. It was about ratios really but you could have worked it out using formulae.
For the ratio I got 30 which seemed like a nice number. For the orbit I got 87.5 days I think.
Overall I thought that section A was relatively easy. Section B was quite straightforward but seemed to include little bits where you really had to think. It also contained lots of written answer and quite a few graphs and diagrams to complete. -
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Hurrah! I believe I got 30 for the ratio also, orbit was 87.5 days (did you have to say earth days!?(Original post by ryan342)
Yeah, the answer was 40mm for the charges. It was potential so the force due to each charge was inversely propertional to the distance between them. It was about ratios really but you could have worked it out using formulae.
For the ratio I got 30 which seemed like a nice number. For the orbit I got 87.5 days I think.
Overall I thought that section A was relatively easy. Section B was quite straightforward but seemed to include little bits where you really had to think. It also contained lots of written answer and quite a few graphs and diagrams to complete.
) and I did 40mm for the zero potential point.
Ill get back to you with what ever else I can remember from Section A, tell me what you think... -
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Hmmm in no particular order here's what I can remember of the fifteen questions from Section A...
1. Lowest point of mass spring system = least kinetic energy
2. Pendulum time period doubled, length + 0.3 = original length of 0.1m
3. Polarised sunglasses = polarisation when light reflects off ground
4. Path difference pi/3 = I forget what the answer was
5. Electron, gravitational force / electric force = the bottom one I think, D
6. Earth has g, density is doubled, radius is doubled, new gravity = 4g
7. +4 -16 , charges, 120mm, zero volt point = 40mm from x
8. Electron in field, motion = opposite to field direction
9. Gradient of gravitational potential vs distance = gravitational field strength
10. Straight through compared to third order = 42 degrees
11. ...
12. Half cycle later of progressive wave = P falls, Q rises and falls
13. ...
14. Incorrect purpose of control rods = slow down neutrons
15. Flux vs induced emf graphs = square graph, big block first
How does that compare to you guys... ?
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Hmm i found mod 4 really easy but i got different answers than you lot so hmmm...
I put 24 mm for the charge one, because the total charge was 20, 4/20 * 120 = 24mm
Also got something like 7000days for the orbit and the ratio was 8*10^18 or something.
Bah
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got the same for nearly all apart from 7 and 15. on 15 i put the same graph as the E one as it is proportional to it.(Original post by deity47)
1. Lowest point of mass spring system = least kinetic energy
2. Pendulum time period doubled, length + 0.3 = original length of 0.1m
3. Polarised sunglasses = polarisation when light reflects off ground
4. Path difference pi/3 = I forget what the answer was
5. Electron, gravitational force / electric force = the bottom one I think, D
6. Earth has g, density is doubled, radius is doubled, new gravity = 4g
7. +4 -16 , charges, 120mm, zero volt point = 40mm from x
8. Electron in field, motion = opposite to field direction
9. Gradient of gravitational potential vs distance = gravitational field strength
10. Straight through compared to third order = 42 degrees
11. ...
12. Half cycle later of progressive wave = P falls, Q rises and falls
13. ...
14. Incorrect purpose of control rods = slow down neutrons
15. Flux vs induced emf graphs = square graph, big block first
How does that compare to you guys... ?
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Come to think of it, that is the exact calculation I did:(Original post by Laffo)
Hmm i found mod 4 really easy but i got different answers than you lot so hmmm...
I put 24 mm for the charge one, because the total charge was 20, 4/20 * 120 = 24mm
Also got something like 7000days for the orbit and the ratio was 8*10^18 or something.
Bah
4/20 * 120 = 24mm
I think that from reading the start of the thread I got brainwashed that I put 40mm! I did in fact mean 24mm.
Hmmmm 7000 days, looks like you didn't square root it ?
Ratio im pretty certain was 30...
7 as above! 15, im pretty sure E is the gradient of flux density against time, if I recall the question it was about a magnet being moved towards the coil and since induced emf is equal to the rate of flux change you needed the gradient; hence the square graph with the big block first(Original post by Laffo)
got the same for nearly all apart from 7 and 15. on 15 i put the same graph as the E one as it is proportional to it.
Im glad to see we agree on most! Looks good
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(Original post by deity47)
Hmmm in no particular order here's what I can remember of the fifteen questions from Section A...
1. Lowest point of mass spring system = least kinetic energy
2. Pendulum time period doubled, length + 0.3 = original length of 0.1m
3. Polarised sunglasses = polarisation when light reflects off ground
4. Path difference pi/3 = I forget what the answer was
5. Electron, gravitational force / electric force = the bottom one I think, D
6. Earth has g, density is doubled, radius is doubled, new gravity = 4g
7. +4 -16 , charges, 120mm, zero volt point = 40mm from x
8. Electron in field, motion = opposite to field direction
9. Gradient of gravitational potential vs distance = gravitational field strength
10. Straight through compared to third order = 42 degrees
11. ...
12. Half cycle later of progressive wave = P falls, Q rises and falls
13. ...
14. Incorrect purpose of control rods = slow down neutrons
15. Flux vs induced emf graphs = square graph, big block first
How does that compare to you guys... ?
Well done on managing to remember all those! Most of them look the same as what I got. Not sure if I might've got something different on question 10 though. Think I got sin Ø = 1/3, Ø = 19 although that might've been a different question on a different paper Can anyone remember the whole question for 10?
Wasnt sure on question 15 but sounds like I got it right
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The angle between the waves diffracted through to give the second order maximum against the straight through position when the slit width is equal to 3λ. Therefore:(Original post by davedave)
Well done on managing to remember all those! Most of them look the same as what I got. Not sure if I might've got something different on question 10 though. Think I got sin Ø = 1/3, Ø = 19 although that might've been a different question on a different paper Can anyone remember the whole question for 10?
Wasnt sure on question 15 but sounds like I got it right
dsinθ=nλ
3λsinθ=2λ
sinθ=2λ/3λ=2/3
θ=42°
Considering the straight through is zero degrees, theres your answer! I hope
