[steviep14]

UNOFFICIAL P3 Mark Scheme - 30.5.12 - AQA GCSE

Thanks to: AaronGreatBanks too

Where there is "underlining" and "bold" it means it is required for the mark
List principle applies - Incorrect + Correct = Wrong

Q1 - Circular Motion
1a) Towards the centre of the circle (Maybe: Accept towards the mass) (1)
1b) Tension in the rope (1)
1c) Any TWO from:
- You can only have one independent variable
- It would alter the results etc. - (Idea of "ruining the experiment here")
(Any more??) (2)
1d) So that their results were more reliable (Maybe: Accept it is hard to count only one spin accurately) (1)
1e) Continous , Dependent (1) (Both needed for 1 mark - Apply List Principle - One / Three-Four ticked = 0 Marks
1f) The bigger the centripetal force, the faster the speed needed to keep it moving in a circle
(Accept Greater/Bigger - Accept Converse - Ignore Answers relating to proportion - Positive Correlation is insufficient for mark) (1)

Q2 - Centre of Mass
2a) Any THREE from:
- Hanging card by holes on stand (owtte)
- Placing Plumbline on the card (to find the centre of mass)
- Drawing line along the piece of string of the plumbline etc.
- Where the two lines cross is the centre of mass
(Allow any sensible suggestions) (3)
2b) - Balance object on Centre of Mass / Draw a third line - (Idea of proof / improvement) (2)

Q3 - Satellites
3a) Gravity (between Satellite and Earth) - Do NOT accept "weight" (1)
3b) No
- Geostationary only have one orbit (that had two) (Or Converse)
- It is not orbiting the equator (2)

Q4 - Motor Effect
4a) Any TWO from:
- When the switch is closed, current flows
- The wire experiences a force when a current flows in a magnetic field
- (The wire goes upwards as a result of current) - Maybe not worth a mark at all (2)
4b) The Motor Effect (1)
4c) The wires direction of movement would be reversed five times every second (2)
4e)0.005 N (2) - 1 for Working and ecf - 2 for answer without or with working

Q5 - Sound
5a) Same amplitude(1)
5b) The first notes is a smooth sound whereas the second notes is a sharp, brassy sound - Or reference to purity of the note - idea of different appearance - Also Accept "Different Waveform" (1) - Do NOT accept references to "Frequency/Amplitude"

5c) The amplitude (1)
5d) Any TWO from:
- The lady cannot hear below 50dB
- The average speaking voice = 45dB so she cannot hear it properly
- The essential speaking range = 500-2000Hz
- Idea that a hearing aid will amplify normal volume to volume she can hear etc. (2)
5e) Crosses across twenty from 250-20000 Hz - Do not accept crosses above 20 on Y-Axis - Min. 5 Crosses - Accept the crosses anywhere between 0 and 20 and in the shape of the curve provided in preceding graph (1)
5f) Because it can damage their hearing / Idea of needing to know to prevent risk etc. (Accept: Dangerous to them so need to be warned) (1)
5g) Because in the hall the sound will reflect off the walls meaning more of the sound is "retained" meaning that the sound is louder (Or Converse) - Also Accept: "More molecules packed in" idea (1)

Q6 - Transformers
6a) Step Up (1)
6b) More Coils on Secondary Coil than Primary Coil (1)
6c) Iron is magnetic / It can produce an alternating magnetic field - Do NOT accept "it conducts well" (1)
6d) 60 Turns (2) - 1 for Working, 1 for Answer - Award 2 for Answer with or without working

Q7 - Lenses
7a) Diverging lens (1) - Credit: "Concave Lens" - But do NOT accept "Concave" unless lens is quite clear and do NOT accept reference to "Rays" - Lens is the key idea
7b) Any THREE From:
- Ray horizontal/perpendicular to object to the lens and refracting
- Ray from the object tip to the point where the axis and the lens meet and refracting
- Correct drawing of Final Image - (Incl. Correct use of dotted lines)
- Quality of Drawing and Arrows used (3)
7c) 0.5 (2) - Or: ECF from 7b) - Their Image Height / Object Height for 2 marks - 1 mark for Working, 1 for Answer - Award 2 with or without working
7d) ONE from:
- Formed by virtual rays
- No real rays pass through the image
- (Maybe: "Formed on same side of the lens") (1)

Q8 - Life of a Star
8a) The Star runs out of Hydrogen fuel, preventing nuclear fusion - Ignore: "Fission" and wrong spelling to be confused with Fusion (1)
8b) Any THREE from:
- The star expands to form a Red Giant (and heats up)
- The Red Giant then turns into a White Dwarf Star (and cools)
- Relative Luminosity Increases then Decreases etc. - Accept: "It gets brighter then duller (owtte)"
(Any others??) (3)

Predicted Boundaries: (Don't expect me to be right though - It definitely was hard )
Grade Boundaries are devised by how hard the paper was on national average - Not years before or personally but this year's average!
31 A* -- (Unlikely to Exceed 33 or Fall Below 29)
27 A -- (Unlikely to Exceed 30 or Fall Below ~25)
21 B -- (Unlikely to Exceed 25 or Fall Below 18)
16 C? -- (Unlikely to Exceed 20 or Fall Much Below 15)

Please Note: AQA are expected to raise boundaries this year - Therefore an A* may well be 35 and an A 30 etc.
However, this isn't confirmed

Please suggest what else to add!

Thanks to Aaron for also starting this - I have just added more Enjoy!

Spoiler:

Show

100 UMS - 34 Marks
97 - 33
93 - 32
90 - 31
87 - 30
85 - 29
82 - 28
80 UMS -27 Marks
78 - 26
76 - 25
74 - 24
73 - 23
71 - 22
70 - 21
68 - 20
66 - 19
64 - 18
62 - 17
60 UMS - 16 Marks

Find the Discussion Thread here:
http://www.thestudentroom.co.uk/show....php?t=2003462

Credit for more stuff from:
Dugald

[letsbehonest]

Based on this .. I got 37

Is nuclear fusion reallllllllly needed to get the mark blergh annoying

[Rukhsaar]

Thank u soo much but u'v made me realise that i've failed

[steviep14]

(Original post by letsbehonest)
Based on this .. I got 37

Is nuclear fusion reallllllllly needed to get the mark blergh annoying

Well what did you write?

I would assume - "Hydrogen fuel runs out" should get the mark
"Hydrogen fuel runs out stopping nuclear fusion / the reactions" etc. Will secure the mark..
I would think you would get the mark

[steviep14]

(Original post by Rukhsaar)
Thank u soo much but u'v made me realise that i've failed

Well what mark did you get.. I mean, my mark scheme and grade boundaries are not set in stone by any means..
There are bound to be more answers for marks and the grade boundaries may be lower..
This is only a guide

[ChemicalFreak]

i found this exam soo hard! it was nothing like the past papers!!

[Maisie10]

thanks so much for this, however in 7a it had already stated in the question that it was a lens so why would it be necessary to repeat lens after concave to get the mark?
reckon ive got between 25-31 going from really harsh marking to being quite lenient! so i should have got my B to get an A overall

[Maisie10]

also in 8a i'd had a complete (stupid) mindblank and couldnt remember if it was hydrogen or helium, so i put both do you think they would they accept it as i did mention hydrogen runs out so no nuclear fusion cant take place, however i did say helium as well!

[saycrackagain]

CAN SOMEONE LINK THE P2 UNOFFICIAL MARK SCHEME PLEASE?!

... That is, if there is one.

[Henchy]

Did anyone put geostationary for Q 3 coz im sure it was around the equator? :/

[steviep14]

(Original post by Maisie10)
thanks so much for this, however in 7a it had already stated in the question that it was a lens so why would it be necessary to repeat lens after concave to get the mark?
reckon ive got between 25-31 going from really harsh marking to being quite lenient! so i should have got my B to get an A overall

Hmm.. "Concave" may just be ok then "Concave Lens" is definitely fine though.. I would think "Concave" will be ok too

(Original post by Maisie10)
also in 8a i'd had a complete (stupid) mindblank and couldnt remember if it was hydrogen or helium, so i put both do you think they would they accept it as i did mention hydrogen runs out so no nuclear fusion cant take place, however i did say helium as well!

hmm.. Right + Wrong = Wrong I don't think so for that one.. I think putting helium may negate the mark.. but then again it may not..

[klioo28]

want to die got soo many wrong! why was the exam so hard??????

[saycrackagain]

lol 5e i did crosses all along Such a stupid mistake! This exam was quite tricky, nevertheless, i think i scraped a 40 in accordance to this mark scheme. So, so chuffed!


Im pretty sure that for 6C, "Iron is easily magnetised" would be the correct phrase. "Magnetic" is usually discarded in official mark schemes.


5f is so simple O_O Oh dear god, i went overboard on that one, going on about how earbuds having closely packed together particles (solid), and how sound travels faster in denser mediums, therefore this would damage the hearing. LOL... Embarrassing much? The answer is so concise!

[Zozzy]

THANK YOU SO MUCH FOR POSTING THIS MARK SCHEME, I was really worried that I'd failed, but it looks like I've got 36-38 which hopefully should be enough for an A*, is there an unnofficial mark scheme for the p2 yet?

[Zozzy]

is it true that they are putting up the grade boundaries this year for all the scieneces becuase this is what my teachers have been saying I really hope they're not

[katiehackett]

(Original post by Henchy)
Did anyone put geostationary for Q 3 coz im sure it was around the equator? :/

Yeah, it also said 24 hours so it must be geostationary...I think he got that wrong?

[adamsharif]

Lol from this mark scheme i've got 27-29 :|
I made so many stupid mistakes
lmao i put converging instead of diverging like an idiot :L

[steviep14]

(Original post by katiehackett)
Yeah, it also said 24 hours so it must be geostationary...I think he got that wrong?

2 things:

1) It wasn't orbiting the equator.. if you looked closely it was orbiting the poles and it wasn't in line with central Africa

2) It said "twice" in 24 hours, suggesting it cannot be Geostationary

I am pretty sure it is right

[spyzapper25]

For 6b can you have more turns in the secondry coil.?

[DrumChops]

(Original post by steviep14)
5g) Because in the hall the sound will reflect off the walls meaning that the sound is louder (Or Converse) (1)

Something wrong here!

This does not necessarily mean that the sound is "louder". Just because sound reflects doesn't means the amplitude is greater. The point was, there are more molecules for more mechanical vibrations/reverberations (i.e. due to densely packed molecules in the walls) when you're inside.

Overall, I think achieved enough for an A* in Physics overall so I'm happy.