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IGCSE Physics - 1P - 14th May 2013

I didn't really think there were that many to learn. Which are you learning?

Exactly what I was asking, but just found in the revision guide it says 'you should be able to describe an experiment to demonstrate conversation of momentum'. Can't seem to find much else though.

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Reply 41

parasagarwal01

Guys.. I just asked some guy.. Although he isn't "related" to edexcel but he has always noticed that an intro into a new specification series means that the exams are highly likely to be easy BUT as a result many people do well so the grade boundaries rise thus making it harder to acheive an A*.

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Reply 42

apoorvahk

13

Guys, if you want a list of experiments for IGCSE (DOUBLE SCIENCE) only, you could try this https://docs.google.com/a/kgv.hk/presentation/d/1ISHcSQKjZjqdU15Lp7qA2oyEn8sfm-n3r559ehjGPwE/edit#slide=id.p24 :smile:

If you can access it though, since it's made by our school! You can try, hope it works and good luck everyone for Physics tomorrow!

Reply 43

Navo D.

2

Okay now I'm panicking :s Do you think they'll ask us about radiocarbon dating and gauging? I'm absolutely dreading the "Which student's response is correct? Justify your answer (5)", accompanied by an amusing picture of a thoroughly perplexed student -_-

Reply 44

dathtom

14

Original post by Navo D.

Okay now I'm panicking :s Do you think they'll ask us about radiocarbon dating and gauging? I'm absolutely dreading the "Which student's response is correct? Justify your answer (5)", accompanied by an amusing picture of a thoroughly perplexed student -_-

Draw a moustache on the one you think is wrong :P

Yes they almost alwyas ask about half life, which is pretty easy to remember.

Reply 45

parasagarwal01

Original post by apoorvahk

Guys, if you want a list of experiments for IGCSE (DOUBLE SCIENCE) only, you could try this https://docs.google.com/a/kgv.hk/presentation/d/1ISHcSQKjZjqdU15Lp7qA2oyEn8sfm-n3r559ehjGPwE/edit#slide=id.p24 :smile:

If you can access it though, since it's made by our school! You can try, hope it works and good luck everyone for Physics tomorrow!

Amazing.. Thanks :smile:

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Reply 46

Navo D.

2

Original post by tw15st3d

http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/controlling_current/resistancerev2.shtml
Can anyone explain to me why there is a small flat line on the diode graph just before the current starts to flow?

Diodes have a very large resistance when voltage is applied in the wrong direction. The horizontal line represents this very large resistance (reciprocal of the gradient is resistance) when the voltage is negative. When the voltage is applied in the right direction (forward biased) the resistance is very low, so the graph becomes very steep. Basically, unless that minimum voltage is applied, the diode will not conduct.

Reply 47

TheGrillMan

OP

1

Original post by parasagarwal01

Guys.. I just asked some guy.. Although he isn't "related" to edexcel but he has always noticed that an intro into a new specification series means that the exams are highly likely to be easy BUT as a result many people do well so the grade boundaries rise thus making it harder to acheive an A*.

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Which should still be okay because the grade boundary has never been higher than 140 in the last 4 years (including both Jan and July series).

Reply 48

Navo D.

2

Hmm, are grade boundaries established based on student performance only? Or is it a mixture of that and also how difficult the examiners considered the paper was?

Reply 49

amalik_

Could someone please explain when total internal reflection occurs in regard to the angle of incidence/critical angle?
Like, when a ray of light hits a boundary at an angle greater (?) than the critical angle (?).........

Reply 50

Navo D.

2

Total internal reflection occurs when the angle of incidence (i) is greater than the critical angle. Do you want a mathematical explanation/reasoning?

Reply 51

amalik_

Original post by Navo D.

Total internal reflection occurs when the angle of incidence (i) is greater than the critical angle. Do you want a mathematical explanation/reasoning?

Thanks, is that it? If they ask for, let's say, a 4 mark question saying 'describe the process of total internal reflection in the glass block' what would you say (if you don't think this could even be a possible question then don't bother). And sure, go for it :smile:

Reply 52

TheGrillMan

OP

1

Original post by amalik_

Thanks, is that it? If they ask for, let's say, a 4 mark question saying 'describe the process of total internal reflection in the glass block' what would you say (if you don't think this could even be a possible question then don't bother). And sure, go for it :smile:

You would talk about the difference of optical densities of the media. Ie it goes from more to less optically dense.

Reply 53

Navo D.

2

Oh boy, here goes;

When light passes from an *optically* denser medium to an *optically* rarer medium, almost all of the light is refracted from the normal, but some is reflected as well. Now, as the angle of incidence increases, so does the angle of refraction, until the (cue dramatic noise) critical angle. At the critical angle, the refracted ray runs straight along the boundary, and there is still a weak reflected ray inside the glass block/other optically dense medium. However, when the angle of incidence is greater than the critical angle, we get *~total internal reflection*~, i.e ALL of the light is reflected from the boundary. (Remember that critical angles change depending on the medium).

EDIT : okay wow i just realized how borked my mathematical reasoning was, never mind :P

(edited 10 years ago)

Reply 54

amalik_

Original post by Navo D.

Oh boy, here goes;

When light passes from an *optically* denser medium to an *optically* rarer medium, almost all of the light is refracted from the normal, but some is reflected as well. Now, as the angle of incidence increases, so does the angle of refraction, until the (cue dramatic noise) critical angle. At the critical angle, the refracted ray runs straight along the boundary, and there is still a weak reflected ray inside the glass block/other optically dense medium. However, when the angle of incidence is greater than the critical angle, we get *~total internal reflection*~, i.e ALL of the light is reflected from the boundary. (Remember that critical angles change depending on the medium).

EDIT : okay wow i just realized how borked my mathematical reasoning was, never mind :P

That is impressive! And makes more sense now, thank you :smile:

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Reply 55

apoorvahk

13

Can we start a Chem/Bio group for next weeks papers like this one as well?! Thanks! :-)

Reply 56

Navo D.

2

Chem already exists, and I made a bio one recently. Feel free to jon n_n

Reply 57

alexgr97

3

Hi guys,

1) When answering questions about pressure, and it asks you what assumptions you have made, do you say that the mass and temperature/volume remains constant, or the same?
2) Is a definition of refraction - the bending (changing speed or direction) of a wave as it passes through a medium of different density?
3) How do you define critical angle? There seems to be a variety of different answers in different mark schemes.

Cheers!

Reply 58

sa97

2

Original post by Themodfather

How are you all feeling for the french tomorrow. To be honest you need like 80+ out of 100 to get an A* according to the grade boundaries for the last two papers. That is quite hard. What do you guys think will come up in terms of the writing task at the end.
I think perhaps holidays/leisure/environment/technology/transport/future plans

Isn't it 90 raw marks? (60 for reading and writing and 30 for listening). My teacher said that grade boundaries for the A* would be somewhere in the high 70's. It was 72 last year and 81 the year before I think.

Reply 59

sa97

2

Anyone have a good explanation as to why objects like feathers fall more slowly that objects like hammers and coins? I initially thought it was something to with surface area but I think it is more along the lines of terminal velocity.

IGCSE Physics - 1P - 14th May 2013

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