AQA Physics PHYA5 - Thursday 18th June 2015 [Exam Discussion Thread]

Yeah, I did have a browse! I feel good about PHYA4, I can do most of it really well I think, except electric fields. It's odd, I almost always get 90% of the marks on the electric fields part, but I still feel like I know nothing about them???? I'm from Cardiff, so it's WJEC for me🔫 I think my teacher has, but only he's allowed on? Is that normal or does your teacher share it with you?
I completely agree, up until I found out there was no Turning Points it was the best book ever!
So it's not that pushed for time then? That's okay. I really love physics anyway so I've read a few books that cover most of turning points for the written parts, all that will be new is putting the maths to it!


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Hopefully an A... But i have a feeling EMPA will let me down. Any tips for that like how to revise and stuff?

Not sure if it's already been mentioned but what do people think might come up as the 6 marker for astro? Having done most of the past papers the six markers have been atrocious in all but one.


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Also guys, I wasn't the only one who appeared to notice the distinct lack of thermal physics problems, however in the physics B unit 4 papers there are a few odd specific heat capacity questions. Just open them all up as pdf's and hit "ctrl and F" and type in "specific" and all the heat capacity stuff comes up. There aren't an abundance but it's better than none. Happy revising

I'm not sure. I would say telescopes but they could throw in stuff on life cycles of stars. Essentially any topic that you can pick more than 6 points about :/.


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It could be anything really, I think they're the toughest parts of the exam. Something in life cycles on stars would be a godsend though!


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Yeah life cycle would be nice they could make it abstract and ask you to do Ray diagrams on telescopes?


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I don't think they could because the written communication mark couldn't apply then?

It may be possible. Last years PHYA1 QWC asked for a diagram for a thermistor, and the other QWC for PHYA2 was...I think stress strain which required a diagram and graphs? I don't remember them exactly.


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I don't think they could because the written communication mark couldn't apply then?

Idk. Wasn't sure if written communication just meant how well you convey your thoughts, be it diagrams or text haha.


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On the markschemes it usually says something like "The candidate's writing should be legible and the spelling, punctuation and grammar should be sufficiently accurate for the meaning to be clear.", as far as I can tell it's definitely about how well you can write a longer answer using proper paragraphs and spelling things (particularly relevant terms) etc.

Ah I guess that would make sense then. Possible advantages of reflecting telescopes over refracting telescopes? Uses of lenses? CCDs? There are several topics that could make up a six marker on telescopes I think.


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There are definitely a lot of possible six markers in the astro section, comes with the amount of content! Yeah comparisons of telescopes/structures of etc. including at different points on the EM spectrum (that was actually a question I think), how a CCD works has been asked I think but a while ago so still possible for a repeat, life cycle of star stuff has a lot of chances for six markers, H balmer lines, evidence for the big bang is pretty nice but that was on last year's paper so unlikely that we'll see that again (although nothing is impossible)!

Sorry, but could you help me understand what the Balmer series is?

I've heard it has something to do with Hydrogen being in its n=2 state.


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There is a bit on it in my notes, can't remember how in depth it is though. They're pretty important, but I'm guessing you haven't covered them yet then?

So hydrogen in the outer layers of a star can have electrons in the n=2 state. They are then excited by radiation/light emitted by the star to a higher level, and then drop back down to n=2, emitting a photon (same as the process we learnt at AS, just a specific example of it). As electron levels are at specific energies, the photons emitted have specific discrete energies/wavelengths. Before, all the light is travelling towards the observer, but when it's emitted from the H atoms it goes in every direction, so black lines show up on the spectra due to these specific energy photons. This is the Balmer series. Intensity of the lines is dependent on the temperature of a star - cool stars are unlikely to have/will have very faint Balmer lines as the electrons don't have enough energy and are more likely to be in the n=1 state. In really hot stars, they have too much energy and are more likely to be in n=3 or above. In between you get strong Balmer lines due to hydrogen.
In that table of spectral classes etc the last column shows what elements give strong absorption lines for each temperature range of stars