PHYA5 ~ 20th June 2013 ~ A2 Physics

Reply 980

MSI_10

15

Is it necessary to know the laws of thermodynamics? Wasn't taught them in class

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Reply 981

A Pink Monster

1

Original post by BenAdamson

I can't find a single unit 5 (thermal & nuclear) mark scheme! AQA site has the exams but no mark schemes! How useless, can't even find any on 3rd party sites! Help!

http://www.aqa.org.uk/exams-administration/exams-guidance/find-past-papers-and-mark-schemes

You have to click on the markschemes for the options, i.e. the markshemes for the nuclear/thermal bits are included in the various option markschemes (at the beginning)

It's not very clear though, I have to say.

Reply 982

MSI_10

15

Can someone explain balmer lines by bullet points? Textbook wall of texts which don't score any marks are annoying

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Reply 983

BenAdamson

1

Original post by A Pink Monster

http://www.aqa.org.uk/exams-administration/exams-guidance/find-past-papers-and-mark-schemes

You have to click on the markschemes for the options, i.e. the markshemes for the nuclear/thermal bits are included in the various option markschemes (at the beginning)

It's not very clear though, I have to say.

Thanks, that is a very confusing way for them to do it!

Reply 984

OmegaKaos

I think that the optional units should each have their own thread.

As for the core phya5 unit, you guys know about all the experiments that 6 markers could be about right?
There are 8 of them.

100 ums coming my way

Reply 985

bugsuper

8

Original post by OmegaKaos

I think that the optional units should each have their own thread.

As for the core phya5 unit, you guys know about all the experiments that 6 markers could be about right?
There are 8 of them.

100 ums coming my way

which 8 are you referring to?

Reply 986

Lay-Z

20

why is special relativity so hard to understand? :s

Reply 987

cooldudeman

18

Can someone explain why the pattern isn't like the normal pattern

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1371637639925.jpg96.9KB

Reply 988

kingm

10

Original post by cooldudeman

Can someone explain why the pattern isn't like the normal pattern

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What paper is that? Never seen that style of diagram in my life.

Reply 989

D4rth

9

Original post by OmegaKaos

I think that the optional units should each have their own thread.

As for the core phya5 unit, you guys know about all the experiments that 6 markers could be about right?
There are 8 of them.

100 ums coming my way

Which 8?

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Reply 990

sw121

I was reading the astro notes on the aqa website.

it says the absolute magnitude of Antares is -5.3 and absolute magnitude of Proxima century is 15. Both the stars have the same black-body temperature.

according to them the diameter of Antares is 5500 times that of Proxia century.

i did (2.512^20.3)^1/2 and i get the diameter ratio as 11487 times.

can someone please explain how it's 5500 :frown:

Reply 991

OmegaKaos

Original post by bugsuper

which 8 are you referring to?

Rutherford Experiment
Ionisation Chamber
Cloud Chamber
Absorption tests
Geiger Tube
Thermal Reactors
Both for finding specific heat capacity- inversion tube and circuit

Not to mention kinetic theory of gases may come up.

Reply 992

bugsuper

8

The thermal nuclear reactor isn't exactly an experiment. Or, at least, I hope not, because it might be providing the electricity that's charging my laptop as I type

Reply 993

igloo1

Original post by BenAdamson

I can't find a single unit 5 (thermal & nuclear) mark scheme! AQA site has the exams but no mark schemes! How useless, can't even find any on 3rd party sites! Help!

You have to go undere your section B section.. eg, astro, medical physics, and it will be integrated with that markscheme

Reply 994

igloo1

If a question said:
An electrical immersion heater supplies 8.5kJ of energy/sec. Water flows through heater at 0.12kg/s.
masss of water in heating chamber = 0.41kg
i) Assuming all energy is transferred to the water, calculate the rise in temp of water as it flows through heater, in kelvin.
specific heat capacity water = 4200 K/kg/K

ii) water suddenly stops flowing at instant when average temp is 26degrees ( celcius). Mass of water = 0.41 kg
calculate time taken for water to reach 100 degrees if immersion heater continues supplying energy at same rate.

THANK YOU!! :smile:

Reply 995

ehtisham_1

Original post by cooldudeman

Can someone explain why the pattern isn't like the normal pattern

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The sample scatters the electron so that it doesn't pass through the first kens. That's why at the second lens its deflected less.

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Reply 996

cameron95

1

If anyone's doing astrophysics can they help me with a minor query with the H-R diagram. The following diagram (page 30) is the version given in the specification, but I'm not sure about the values on the temperature/class axis. Is each letter at the centre of the class, or is it the space to right (or even to the left)? Thanks in advance.

http://filestore.aqa.org.uk/subjects/AQA-2450-W-TRB-OGA.PDF

Reply 997

kingm

10

Guys, this is the first Q from June 2011. It's an equation for beta- decay and you just have to state the nucleon and proton number:

......Pa → (233/92 U) + (b−) + (anti-neutrino)

The answer i got was 233 nucleons and 91 protons but the mark scheme has 231 nucleons and 91 protons?

Reply 998

D4rth

9

Original post by kingm

Guys, this is the first Q from June 2011. It's an equation for beta- decay and you just have to state the nucleon and proton number:

......Pa → (233/92 U) + (b−) + (anti-neutrino)

The answer i got was 233 nucleons and 91 protons but the mark scheme has 231 nucleons and 91 protons?