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AQA Physics PHYA5 - 28th June 2016 [Exam Discussion Thread]

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Out of curiosity how are gb decided for this unit? Do they take into account everyone's section A regardless of option and then somehow account for the option paper later on or what

On their website they list grade boundaries per option out of 72, but I don't know if there are set boundaries for the first section and it's just for ease of use that they add them together or if it is the total mark that goes towards your grade and the options have different boundaries across both papers.

Reply 1101

C0balt

Original post by Mattematics

I believe they put the marks in a hat and do a lucky dip.

Wouldn't surprise me if this was the case with AQA :wink:

Original post by marioman

The Grade A and Grade E boundaries are set separately for the Nuclear/Thermal paper and each of the option papers. They are added together to give the Grade A and Grade E boundaries for the unit as a whole (depending on which option you took). Then the rest of the boundaries (A*, B-D) are then automatically calculated.

Ah right, thanks :smile:

Reply 1102

jonny7bell

Original post by GCSEHELPPLS

for the mass defect, i didn't see the more accurate atomic unit values for protons and neutrons so i used the 1.673 and 1.675 *10*-27 kg respectively - how many marks will i lose for this due to lack of accuracy -(i got 125 instead of 128 mev due to the said lack of accuracy)

Sorry I'm very worried any help appreciated

Did we get given accurate atomic values for the protons and neutrons? I just used the same method as you above and got 125MeV assuming the extra 3 missing MeV were just down to the different methods used.

Reply 1103

palacefloor

Original post by Wasess786

No its still a real image

would real at infinity give me the mark?

Reply 1104

radiohedge

Original post by koolgurl14

What do you think the GB for applied going to be ? and how did u find it?

FINALLY SOMEONE ELSE WHO DID APPLIED. I found it slightly harder than last year's. I had to leave out a couple of questions and I only half-attempted the six markers, and I want an A. In an ideal world it'd be 55 for an A but I'm worried that's optimistic. What do you think?

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Reply 1105

mofkin

Original post by palacefloor

would real at infinity give me the mark?

Probably not, the image would only be at infinity if the object was placed at. In this case the image would NOT also be magnified, so its really one or the other from infinity/magnified. And unfortunately in our case it was magnified.

Reply 1106

FireBLue97

Was the specific charge 1.8x10^11 Ckg^-1 and if this is wrong how many marks out of 4 will i get

Reply 1107

Yo12345

For the ideal gas one, it says that the gas is such that 1 mole has or cover 0.24m^3 volume. Why would this be in the question for you not to use it?

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Reply 1108

-jordan-

Original post by Yo12345

For the ideal gas one, it says that the gas is such that 1 mole has or cover 0.24m^3 volume. Why would this be in the question for you not to use it?

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You can use it, it's just a ratio they obtained using the ideal gas equation. Gives you the same answer.

Reply 1109

Yo12345

Original post by -jordan-

You can use it, it's just a ratio they obtained using the ideal gas equation. Gives you the same answer.

Density = mass of one molecule / 0.24 in this case?

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Reply 1110

notanooblol

Original post by C0balt

Wouldn't surprise me if this was the case with AQA :wink:

Ah right, thanks :smile:

Hey, what did you get for efficiency on last question of applied?

Reply 1111

Yo12345

Original post by -jordan-

You can use it, it's just a ratio they obtained using the ideal gas equation. Gives you the same answer.

I probably got this question wrong, but I'm sure I've seen one with different values (same Q). How many marks would I gain with my method?

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Reply 1112

-jordan-

Original post by Yo12345

I probably got this question wrong, but I'm sure I've seen one with different values (same Q). How many marks would I gain with my method?

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Method for which? Mols or the density? Density is the correct method if you mean number of mols * molar mass for the mass

Reply 1113

Yo12345

Original post by -jordan-

Method for which? Mols or the density? Density is the correct method if you mean number of mols * molar mass for the mass

My method was to find mass of one molecule (molar mass/Na) and divide that by 0.24

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Reply 1114

kelvin1338

Predictions for A* turning points boundary out of 35, anyone? Most people in my class said turning points was hard this year but the compulsory nuclear physics section A was nice

Reply 1115

Yo12345

Original post by kelvin1338

Predictions for A* turning points boundary out of 35, anyone? Most people in my class said turning points was hard this year but the compulsory nuclear physics section A was nice

28? And 32 in Section A?

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Reply 1116

-jordan-

Original post by Yo12345

My method was to find mass of one molecule (molar mass/Na) and divide that by 0.24

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The Avogadro is the number of particles in one mole. But the molar mass is the mass of one mole. So you've found the mass of one particle, not the whole gas. I'd say you've most likely dropped one mark.

Reply 1117

Yo12345

Original post by -jordan-

Out of 2? Not too bad

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Reply 1118

Fbiemad

1- Is the unit of J/kgC (C= degrees celsius) correct for the specific heat capacity?

2- ASTRO: Q1) was it 0.9 or 0.18? So did we take the given focal point of 0.15 as (fe) or as (fo)?

3- ASTRO: - Was the 3rd star "41-Aries..." The furthest one?
- In the essay, which region did each star belong to?

Please in your reply, let me know how confident you are in your answers for these questions.