[mora11]

(Original post by Lilmzbest)
thanks so much, have been worried that i totally failed, but i think i stand a good chance at getting an overall B (i got around 80 in this, but i needed 130 UMS for an A)

80/100 Will most likely be an A grade.

[mashmammad]

(Original post by mora11)
**** off dickhead he spends time making these when he doesn't have to so he can help people out? I suspect you scored full raw marks in this exam and you are going to oxbridge next year with you 6A*s at a-level get a life you prick

You should be ashamed for your language. Yes I'd love to go to Cambridge and get the full ums. But so do you. But if you are not stupid enough to ignore this part I must say atoms also have energy eg an atom of hot metal has higher internal energy as they have more ke but they don't emit photon. Now judge yourself, who should get a life.

This was posted from The Student Room's Android App on my HTC Wildfire

[mora11]

(Original post by mashmammad)
You should be ashamed for your language. Yes I'd love to go to Cambridge and get the full ums. But so do you. But if you are not stupid enough to ignore this part I must say atoms also have energy eg an atom of hot metal has higher internal energy as they have more ke but they don't emit photon. Now judge yourself, who should get a life.

This was posted from The Student Room's Android App on my HTC Wildfire

someone is jelly of my offer from trinity college, and based upon col's answers I have around 95/100 which is probably max ums umad?

[mashmammad]

(Original post by mora11)
someone is jelly of my offer from trinity college, and based upon col's answers I have around 95/100 which is probably max ums umad?

I don't care. You won't be a successful person if you continue to speak like that whatever your state is. Not in a hundred years. You are still a 5 years old child. Grow up. I sent a point to be considered as he said he is going to edit his answers. I wasn't even talking to you or asking your opinion.

[Theafricanlegend]

(Original post by mashmammad)
Q7 a) i) Photon is emitted when atom moves from higher to lower energy level
dont wanna be pedantic but it should be electron.

yeah thats what i wrote, i really want an a...i dont understand how people find physics easy, probs my teacher is rubbish! atleast im so much better at other sciences

[Theafricanlegend]

(Original post by mora11)
**** off dickhead he spends time making these when he doesn't have to so he can help people out? I suspect you scored full raw marks in this exam and you are going to oxbridge next year with you 6A*s at a-level get a life you prick

woah man/woman calm it! and as you got 95/100 could you please tell me how you revised? did you use a revision guide? i reallly need help for an a?? thanks appreciate ANY ADVICE

[Lilmzbest]

(Original post by mora11)
80/100 Will most likely be an A grade.

yeah looking at past boundaries i think 80 will give me an A in this exam, but i'm not sure if i'll get the 130 UMS to get an A overall, might if i'm lucky though

[mashmammad]

(Original post by lilmzbest)
yeah looking at past boundaries i think 80 will give me an a in this exam, but i'm not sure if i'll get the 130 ums to get an a overall, might if i'm lucky though

this jan my mate dropped 9 and got full. So there is a chance of you getting 130 ums.

[Lindizya]

got around 70-75 depending on method marks in questions i got wrong hopefully that's a B

[Lilmzbest]

(Original post by mashmammad)
this jan my mate dropped 9 and got full. So there is a chance of you getting 130 ums.

that would be awesome, cos i really wanted 5 As and it didn't look like chem or phys were going to get past a B...but an A in this would make me happy

...lol chem will still be a fail though, but oh well

[mora11]

(Original post by Theafricanlegend)
woah man/woman calm it! and as you got 95/100 could you please tell me how you revised? did you use a revision guide? i reallly need help for an a?? thanks appreciate ANY ADVICE

I used the guide from OCR it's a small one our sixth form supplied us with it.
I learnt the content from the book and then did all the papers from the OCR website. I had done extremely similar questions to all that was on the actual paper (except the last one) so I was confident in my answers. Based upon col's mark scheme I predict 90/100 for me which fingers crossed is full ums. Good luck

[Theafricanlegend]

(Original post by mora11)
I used the guide from OCR it's a small one our sixth form supplied us with it.
I learnt the content from the book and then did all the papers from the OCR website. I had done extremely similar questions to all that was on the actual paper (except the last one) so I was confident in my answers. Based upon col's mark scheme I predict 90/100 for me which fingers crossed is full ums. Good luck

do you recommend cgp? and can you link me?

[teachercol]

I like the CGP book - but its not from OCR. Its a common misconception. OCR dont produce any books. Teachers produce books which the OCR endorses. All this says is that it matches their syllabus. They arent 'official' books in any sense.

[mora11]

(Original post by Theafricanlegend)
do you recommend cgp? and can you link me?

http://www.amazon.co.uk/OCR-Physics-.../dp/B006TH9Q8K

There you go.

[mora11]

(Original post by teachercol)
I like the CGP book - but its not from OCR. Its a common misconception. OCR dont produce any books. Teachers produce books which the OCR endorses. All this says is that it matches their syllabus. They arent 'official' books in any sense.

This http://www.amazon.co.uk/OCR-Physics-.../dp/B006TH9Q8K is the book we were given. Very good actually, hopefully it has done enough to secure me that A in need!

[Theafricanlegend]

(Original post by teachercol)
I like the CGP book - but its not from OCR. Its a common misconception. OCR dont produce any books. Teachers produce books which the OCR endorses. All this says is that it matches their syllabus. They arent 'official' books in any sense.

(Original post by mora11)
http://www.amazon.co.uk/OCR-Physics-.../dp/B006TH9Q8K

There you go.

thanks.. sorry for the questions! but. do you guys reccommend both units g485 g484 of the same type of book (the one you linked me) or the a2 cgp book?

[Theafricanlegend]

(Original post by teachercol)
Usual disclaimer. These are just my answers and are in no sense official.
They may contain erros and typos.

Q1 a) Power = rate of doing work or Work done per unit time (1)
b) i) P=VI so I = 40/230 = 0.17(4) A (2)
ii) R-V/I (or use P = I^2R) R = 230/0.174 = 1320 ohm (2)
c) R = rho L/A so L = 1320 x 3.0E-8/7.0E-5 = 0.567m (3) ecf
d) If same PD bigger power must have more current (P=VI)
so R must be smaller so A must be bigger so must be thicker (3)
e) i) Q=It = 0.174 x 8 x 3600 = 5011C (2) ecf
ii) 1) kW.h = ENERGY converted by a device of power 1kW operating
for a time of 1h (1)
2) Energy = 40/1000 x 8 = 0.32kWh
so cost = 0.32 x 22 = 7(.04)p (2)
Total 15

Q2 a) i) 1) R is infinite below 1.4V (1)
2) When V=1.8v, I = 10mA so R=1.8/10E-3 = 180ohm (2)
ii) R gets smaller. Current is increasing faster than PD.
or just calculate R at different points. (3)
NB Ohm's law doesnt apply here- graph not a striaght line through the origin
R is NOT the gradient. R=V/I not dV/dI
b) Draw LED (right way round ) with ammeter/ voltmeter and resistor in right places.(4)
c) LED used for torch bulbs / car headlights.
More efficient becasue they produce less heat. Lower running costs. Longer lifetime. (2)
Total 12

Q3 a) When temp rises, Rtherm falls, Total R falls, cureent increases. (3)
b) Either use potential divider or use Total R and work out current then PD.
Rtherm = 40ohm so ratio of R is 200:40 so PD must split in same ratio 5:1
so PD=5v (4)
c) i) Draw LDR symbol (1)
ii) When light intensity increases, R falls so ratio Rldr:R200 must drop
so PD across 200ohm resistor must increase.
or total R drops so current increases so PD across 200 increases. (2)
Total 10

Q4 a) PD across 6ohm = IR = 0.30A x 6.0ohm = 1.2v
In parallel so same PD so I = V/R = 1.2/6.0 = 0.20A
b) i) Kirchoff's 1st law (1)
ii) I = I1 + I2 = 0.30 + 0.20 = 0.50A (1)
c) 1/Rp = 1/R1 + 1/R2 = 1/6 + 1/4 = 5/12
Rp = 12/5 = 2.4ohm
Total R = 2.4+5.6 = 8.0 ohm (3)
d) i) Emf = energy converted per unit charge
from one form of energy to electrical energy in a source (2)
ii) Terminal PD = PD across combination = 0.50 x 8.0 = 4.0v (1)
(or add up Pds)
iii) V = E - Ir
4.0 = 5.0 - 0.50r so r = 2.0 ohm (2)
Total 12

Q5 a) e has charge / photon doesnt
e has mass / photon doesnt
photn travels at c / e cant (2)
b) i) Gain in energy = QV = 1.6E-19 v 5000 = 8.0E-16J (2)
ii) Energy = 1/2 m v^2
8.0E-16 = 1/2 x 9,1E-31 x v^2 so v = 4.2E7 ms-1 (3) ecf
c) i) Wavelength of probability wave associated with electron (1)
(not sure what they expect here. )
d) E = hf
8.0E-16 = 6.6E-34 x f so f = 1.21E18 Hz
lambda = c/f = 3.0E8/1.21E18 = 2.48E-10m (3)
e) i) Photoelectric effect (1)
ii) max KE = hf - phi
= 9.0E-19 - 7.2E-19 = 1.8E-19
iii) phi is min energy needed to release an electron from surface.
deeper electrons need more energy
so have less KE. (2)
Total 19

Q6 a) i) Displacment = distance moved from equilibrium in a specified direction
Amplitude = max displacment (2)
ii) Frequency = no of complete oscillation per unit time
Phase difference = measure of how much out of step two
oscialltions are measured in fractions of a cycle
or as ana angle 0-360 or 0 - 2pi (2)
b) Diagram is essentially mirror imaged. Wave travels 0.25m every 0.5s (4)
Total 8

Q7 a) i) Photon is emitted when atom moves from higher to lower energy level
Energy of photon = hf = hc/lambda= difference in energy of two levels.
so One wavelength corresponds to one transition between higher / lower energy level
three possible transitions (3-2, 3-1 and 2-1) so three different wavelengths (3)
ii) 1) f = v/lambda = 3.0E8/6.56E-7 = 4.57E14Hz
E = hf = 6.6E-34 x 4.57E14 = 3.0E-19J (2)
2) Photon energy Must be difference btween energy of levels
so must be 3-2 (1)
b) i) 1) lambda = d sin theta so d = 6.56E-7 / sin 11.4 = 3.32E-6
2) N = 1/d = 301306 lines per m
= 301 lines per mm (1)
ii) Blue has smaller lambda
sin theta = lambda / d d is same so theta is smaller (1)
Total 11

Q8 a) same speed / travel through vacuum / E and B fields oscillate (2)
b) uwave = 1E-4 / UV = 1E-8 / gamma = 1E-12 / IR = 1E-6 (2)
c) i) Receiver reflects incident wave back at 90 but some is absorbed (freq stays same)
so reflected wave has lower amplitude and same freq than incident wave (2)
ii) Waves superpose. R detects resultant amplitude
At some points waves are in phase / reinforce and give maxima
At other points waves are 180 out / cancel and we get minima (3)
iii) max - min = 7.5mm
so lambda = 4 x 7.5 = 30 mm (1)
iV) Max amp = 0.8a + 0.6a = 1.4a
Min amp = 0.8a - 0.6a = 0.2a
I is prop to square of amp
so ratio = (1.4a/).2a) ^2 = 49 (3)
Total 13

I thought this was quite an easy paper but the feedback I've had was mixed.
Some people really liked it, others hated it.

There wasnt much in the way of descriptive stuff, a lot of calcualtion.
It probably suits mathematically inclined students.

I still think its easy so grade boundaries may not be as low as they have been.

No - I cant tell you how many UMS you'll get. Dont ask.

Remember me?! I got 124/150 meh not bad but still an A so in raw is that 75?

[kanojyoxx]

(Original post by Theafricanlegend)
Remember me?! I got 124/150 meh not bad but still an A so in raw is that 75?

By the UMS calculator I downloaded, 124 is 75 raw, but then again it says my score (135) is 73 raw!

Edit: I've worked it out by myself.

124 UMS should be around 77 raw marks (124.4 recurring by my calculations).

My 135 is either 87 or 86 raw marks.