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AQA Physics PHYA1 - 24 May 2016 - RESIT [Exam Discussion Thread]

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Original post by TajwarC
No. This exact question came up before in a paper (June 14) and the reasoning behind the neutral pion was to conserve charge, except they gave you a list of particles to chose from. I'll be honest here, aside from the obvious charge conservation the only reason I knew it was the neutral pion was because I'd seen the question before

That's A levels for you haha. You might get the mark, who knows


Exactly this, they asked us the same thing in June 14 Q1ci - that's the only reason why I knew.
Original post by Ayaz789
It varies a lot that the thing!(
June 15- 41
June 14- 46
June 13- 49
Jan 13- 48
June 12- 47Jan 12- 47


Predict the grade boundaries on how you found the paper compared to the past papers and see what you need.
Original post by TheLifelessRobot
Predict the grade boundaries on how you found the paper compared to the past papers and see what you need.


Haha to get 75 Ums ill need 45/70 tbh
Original post by matty9
For the conservation to find particle X I put photon, it doesn't have a charge, lepton number = 0, baryon number = 0, doesn't violate anything so would I by any chance get the mark?


You'll probably get marks for saying charge and lepton number has to be conserved but photons (virtual) are exchange particles for electromagnetic interactions so you wouldn't get the final mark for identifying X. I'd assume it's 3/3 marks for simply stating its a neutral pion because it didn't ask for any explanation.
Reply 444
Original post by BanterBus
You'll probably get marks for saying charge and lepton number has to be conserved but photons (virtual) are exchange particles for electromagnetic interactions so you wouldn't get the final mark for identifying X. I'd assume it's 3/3 marks for simply stating its a neutral pion because it didn't ask for any explanation.


Yeah it didn't ask for an explanation which confused me in the exam because it normally did, I wrote the conservation laws anyway so hopefully should pick up 1 or 2 out of 3
Is there an unofficial mark scheme?
How many marks was all the heater question
Original post by Imtheish
How many marks was all the heater question


14
Honestly didn't think it was too bad, I'd say around 55 ish for an A. The only question that threw me off was the heating element one, specifically part C and D. If the answers in here are anything to go by, I'd say I've got around 60 imo.
Original post by emsieMC
I got 3.4 ohms for internal resistance


Yeah, got that too. Should have full marks for that question if you got that.
[QUOTE="Adamwest17;65130195"]14[/QUOTE
Thanks what about the whole question about the internal resistance
Original post by lucabrasi98
Last years paper was genuinely disgusting though. It's normally around 55-58 for an A but they had to drop it to 49 because of how many marks were dropped overall. I think it'll go back up to 55-58. There's no year 12s taking it and the paper wasn't that bad.


smh. I still don't understand why aqa assumed we'd know the last question in the june 2015 paper was a parallel circuit. Or why I was tested on potato conduction.


Its usually around 53 for an A from what I have seen :smile:
[QUOTE="Imtheish;65130565"]
Original post by Adamwest17
14[/QUOTE
Thanks what about the whole question about the internal resistance


Think 10
Also was the peak to peak question singular? I mean if you had a wrong answer there im guessing you wouldnt get further questions wrong?
Question 7 Everyone:
IMG_1196.jpg
Original post by Formless
Everyone please correct, suggest and add. Rep is appreciated,
What i got so far.
1) isotope - same no. protons, diff no. neutrons
92*1.6*10^-19/mass no. * 1.67*10^-something I got 3.7 * 10^something 3 electrons removed to 89 fill in -
mass number stays the same, 93 protons, (0, -1 )for beta minus particle and antineutrino
Pair production
Rest Energies of electron and positron must be equal or greater to photon in order to conserve energy. Below energy pair production will not take place
Show that, using (0.51MeV x 2) in data sheet. = 1.02MeV
Photon frequency ( 1.6X10^13/h) = 2.4x10^20 Hz
lepton number conserved (0=0)Kaon decays via weak, so pi 0

Diodes - 6 marker is June 2009, refer to MS
Switch wiring to cell so that opposite flow, Or Switch diode so reverse bias.
Resistance increases, Voltage Decreases. ( i put it so that Res decreases which is wrong as its non-ohmic)

Heating Element BS
V peak to Peak is 650V
4040W, 228V,

7) Current not flowing, therefore dot on the oscilloscope
PQ is Emf=6Volts
current=0.28A,(5/18) I used 5 as it was in parallel with the internal res so voltage has to be 5?.
Internal resistance = 3.6 Ohms. / 3.8 Due to rounding( Using Emf - V = 1)

Prediction - 56/55 For an A


Triple Bumb
And the wire resistance question: IMG_1198.jpg
Original post by Boro12345
Yeah, got that too. Should have full marks for that question if you got that.


How did you get 3.4
Original post by Formless
Everyone please correct, suggest and add. Rep is appreciated,
What i got so far.
1) isotope - same no. protons, diff no. neutrons
92*1.6*10^-19/mass no. * 1.67*10^-something I got 3.7 * 10^something 3 electrons removed to 89 fill in -
mass number stays the same, 93 protons, (0, -1 )for beta minus particle and antineutrino
Pair production
Rest Energies of electron and positron must be equal or greater to photon in order to conserve energy. Below energy pair production will not take place
Show that, using (0.51MeV x 2) in data sheet. = 1.02MeV
Photon frequency ( 1.6X10^13/h) = 2.4x10^20 Hz
lepton number conserved (0=0)Kaon decays via weak, so pi 0

Diodes - 6 marker is June 2009, refer to MS
Switch wiring to cell so that opposite flow, Or Switch diode so reverse bias.
Resistance increases, Voltage Decreases. ( i put it so that Res decreases which is wrong as its non-ohmic)

Heating Element BS
V peak to Peak is 650V
4040W, 228V,

7) Current not flowing, therefore dot on the oscilloscope
PQ is Emf=6Volts
current=0.28A,(5/18) I used 5 as it was in parallel with the internal res so voltage has to be 5?.
Internal resistance = 3.6 Ohms. / 3.8 Due to rounding( Using Emf - V = 1)

Prediction - 56/55 For an A


How would you get 4040? It was literally (230^2)/12=4400. And even if it was 4040, you would be wrong because you had to use 2 significant figures
For the internal resistance I got 3.6 ohms:

The emf was 6.0V, and the terminal pd was 5.0V (worked out from oscilloscope, work out displacement from P to both Q and R and multiply by two).
Resistance of the resistor was 18 ohms, so using V=RI you get I=V/R =5/18 =0.27777... A
Considering the internal resistance, the lost volts were 1V (as emf = terminal pd + lost volts, so lost volts = emf - terminal pd = 6-5 = 1V)
V=RI and R=V/I =1/0.2777777... =3.6 ohms.

You can check that this result is true using the emf equation:
emf = terminal pd + lost volts, so E=IR+Ir
E=(0.27777...)(18) + (0.2777777...)(3.6)
E=6.0V [QED]
(edited 7 years ago)

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