OCR Physics G485 - June 2013 Unit 5 (OFFICIAL THREAD)

OP

Original post by Boy_wonder_95

Currently in the year below but how big is the jump from G482 to G485? :redface:

Unit 1 and 2, you can get A's with poor exam technique as the material is fairly straight forward. Which I did.

A2s builds on AS's so you can't just get through without actually being good at the subject and good at taking exams at A2.

Best to try and nail AS with more than 90% Raw Marks.

Reply 82

Boy_wonder_95

15

Original post by Better

Unit 1 and 2, you can get A's with poor exam technique as the material is fairly straight forward. Which I did.

A2s builds on AS's so you can't just get through without actually being good at the subject and good at taking exams at A2.

Best to try and nail AS with more than 90% Raw Marks.

What UMS did you get in Unit 1 and 2? So far I've only done Unit 2 and got 146 but made A LOT of silly mistakes, definitely wasn't 90% raw :colondollar:

Reply 83

Original post by Boy_wonder_95

What UMS did you get in Unit 1 and 2? So far I've only done Unit 2 and got 146 but made A LOT of silly mistakes, definitely wasn't 90% raw :colondollar:

146/150?? If so, that's insane... but how come you haven't done Unit 1, surely you would do them in order...? :P

Reply 84

Also I found this website that has old specification papers dating back to 2003. There are physics papers for all units, but the link I'll put here should be for G485. It's awkward because of how it's broken down, but still additional questions if anyone wants them.

http://fizx.wikidot.com/g485

Reply 85

Boy_wonder_95

15

Original post by Rhodopsin94

146/150?? If so, that's insane... but how come you haven't done Unit 1, surely you would do them in order...? :P

School decided to do Unit 2 first since its the harder unit and carries a lot more weight; so that people have a chance to resit in the summer if it doesn't go well.
Taking Unit 1 this summer :tongue:

Reply 86

Original post by Boy_wonder_95

School decided to do Unit 2 first since its the harder unit and carries a lot more weight; so that people have a chance to resit in the summer if it doesn't go well.
Taking Unit 1 this summer :tongue:

Fair enough, that does kind of make sense :P and I reckon Unit 1 will complement Unit 4 well (probably better than Unit 2), so good that they are closer together. Wish my school decided to do it that way.

Reply 87

OP

Original post by Boy_wonder_95

School decided to do Unit 2 first since its the harder unit and carries a lot more weight; so that people have a chance to resit in the summer if it doesn't go well.
Taking Unit 1 this summer :tongue:

Well if your keen enough to look at the Unit 5 thread one year ahead you'll do great and given your UMS as well.

Reply 88

OP

I seem to have got a Question wrong on one of the Module 2 Capacitors Questions.

Not quite sure what to do for SERIES Capacitors if your given their respective Capacitance, i.e. C1= 4 C2 = 8 and Voltage = 12

I don't know how you split the Voltage across the capacitors. Does it work in terms of Ratios.

SOMEONE HELP

Reply 89

Original post by Better

I seem to have got a Question wrong on one of the Module 2 Capacitors Questions.

Not quite sure what to do for SERIES Capacitors if your given their respective Capacitance, i.e. C1= 4 C2 = 8 and Voltage = 12

I don't know how you split the Voltage across the capacitors. Does it work in terms of Ratios.

SOMEONE HELP

Basically, because Q=VC, you can work out Q which will be the same across each.

1/Ctotal = 1/4 + 1/8 = 3/8
Therefore Ctotal = 8/3

Back to Q=VC, Q = 12 x 8/3 = 32

Q is the same across each, and V1 = Q/C1 = 32/4 = 8Volts
V2 = Q/C2 = 32/8 = 4Volts

Then to check: Vtotal = V1 + V2 = 8 + 4 = 12Volts

(At least I think that's right)

Posted from TSR Mobile

Reply 90

OP

Original post by Rhodopsin94

Basically, because Q=VC, you can work out Q which will be the same across each.

1/Ctotal = 1/4 + 1/8 = 3/8
Therefore Ctotal = 8/3

Back to Q=VC, Q = 12 x 8/3 = 32

Q is the same across each, and V1 = Q/C1 = 32/4 = 8Volts
V2 = Q/C2 = 32/8 = 4Volts

Then to check: Vtotal = V1 + V2 = 8 + 4 = 12Volts

(At least I think that's right)

Posted from TSR Mobile

Yeah that is 100% right. What if you have Capacitors is Parallel Then what is the charge across them? :s-smilie:

Reply 91

OP

Original post by Rhodopsin94

...

Posted from TSR Mobile

On Second thought what I asked is a Dumb Question.

What is the generalized method you use to solve these types of Questions if you are able to explain it in simple terms?

If it is just use the Voltage and Capacitance rules then that's okay too I just want to know if there is a better way to understand this

Reply 92

Original post by Better

On Second thought what I asked is a Dumb Question.

What is the generalized method you use to solve these types of Questions if you are able to explain it in simple terms?

If it is just use the Voltage and Capacitance rules then that's okay too I just want to know if there is a better way to understand this

Well the module for Capacitors is very short, as you know, so I expect they are just expecting you to be able to remember the key points (i.e. equations such as Q = VC, properties of exponential decay etc - ties in massively with radioactivity etc) and probably the uses bit at the end, since that is 'How Science Works' (always learn that stuff!)

In terms of questions like the one you had trouble with in the other post, I reckon it's a case of recognising the rules that apply for series and parallel, and seeing what you have and how it fits.

Everytime I get a question with numbers in it, I ALWAYS write out what everything is before I do anything OR highlight/underline the figures:

E.g.
Q = ?
C = 2 x 10^-6

(...or whatever it happens to be), then I think of the equations that could apply and use them (if I can't think of one, I revert back to the formulae in the date booklet, although I try to learn these off by heart so that I can tackle questions easier in the first place)

Hope that answers your question.

Reply 93

OP

Original post by Rhodopsin94

Well the module for Capacitors is very short, as you know, so I expect they are just expecting you to be able to remember the key points (i.e. equations such as Q = VC, properties of exponential decay etc - ties in massively with radioactivity etc) and probably the uses bit at the end, since that is 'How Science Works' (always learn that stuff!)

In terms of questions like the one you had trouble with in the other post, I reckon it's a case of recognising the rules that apply for series and parallel, and seeing what you have and how it fits.

Everytime I get a question with numbers in it, I ALWAYS write out what everything is before I do anything OR highlight/underline the figures:

E.g.
Q = ?
C = 2 x 10^-6

(...or whatever it happens to be), then I think of the equations that could apply and use them (if I can't think of one, I revert back to the formulae in the date booklet, although I try to learn these off by heart so that I can tackle questions easier in the first place)

Hope that answers your question.

Kk - boom thanks alot buddy. Yeah you've helped me I will try to finish the remaining questions. Only got 5 more exam style then I'm done for this module.

I really need to pick up the pace, so that I can get onto Mod 4 by the end of Sunday.

On this forum - some have already finished Chem 4/5 notes, and some have finished Phys 5 rev (George.....)

Need to really up my game. C3 C4 and D1 are coming along though fortunately I've gone up a Grade with each paper I've done so far! So need to keep it up

Reply 94

Original post by Better

Kk - boom thanks alot buddy. Yeah you've helped me I will try to finish the remaining questions. Only got 5 more exam style then I'm done for this module.

I really need to pick up the pace, so that I can get onto Mod 4 by the end of Sunday.

On this forum - some have already finished Chem 4/5 notes, and some have finished Phys 5 rev (George.....)

Need to really up my game. C3 C4 and D1 are coming along though fortunately I've gone up a Grade with each paper I've done so far! So need to keep it up

You're doing further maths? I considered it, and my current maths teacher did recommend it to me at the time of applying for sixth form, but I was dissuaded by another teacher, and ultimately decided to pick German instead...(don't ask why)

On a more relevant note... I have C4 coming up in June, although I don't think it'll be that bad, because isn't it partly building on the AS stuff, and then covers vectors (like M1) ? Sadly, I haven't revised much C4 yet at all...

Reply 95

OP

Original post by Rhodopsin94

You're doing further maths? I considered it, and my current maths teacher did recommend it to me at the time of applying for sixth form, but I was dissuaded by another teacher, and ultimately decided to pick German instead...(don't ask why)

On a more relevant note... I have C4 coming up in June, although I don't think it'll be that bad, because isn't it partly building on the AS stuff, and then covers vectors (like M1) ? Sadly, I haven't revised much C4 yet at all...

No haha, I just chose D1 over S1. I wanted to do them both, but my teacher said I would be dumb to do that.

Well yeah Maths is different to Physics and Chemistry so you can actually learn alot in a very short amount of time as long as you are rigorous when you make mistakes. You will do well, I believe in you :h:

Reply 96