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# OCR Gateway Physics P4P5P6 - 18/06/13 Watch

1. If anyone's staying up for a bit and want an extra tricky 12 mark question, I just made one (technically you're practicing for two different potential 6 markers in P6 by doing this!):

Laptops contain computer chips that are supplied by mains AC electricity. The electricity must be 'rectified' and 'smoothed' before reaching the computer chip so it is not damaged.

State which electrical components would be used to achieve this and explain how they work. (12 marks)
2. Well I've been through all 29 pages.. Reason being is because for the Chemistry exam just before leaving the house I was reading some posts on the last page about ion exchange resin which I did not know at all and it came up as 2 to 3 marks in the exam So thank you for the noobs asking questions to the elite one (me) and I wish you all the best of luck with the exam!
3. Funny how things change, I'm no longer doing sciences for A-level :/
If anyone's staying up for a bit and want an extra tricky 12 mark question, I just made one (technically you're practicing for two different potential 6 markers in P6 by doing this!):

Laptops contain computer chips that are supplied by mains AC electricity. The electricity must be 'rectified' and 'smoothed' before reaching the computer chip so it is not damaged.

State which electrical components would be used to achieve this and explain how they work. (12 marks)
AC ---> Step Down Transformer ---> Less Rings on Secondary ---> Diode Bridge Circuit used to create DC electricity ---> Diodes reverse bias dictates a flow that always has output voltage ---> Capacitator used to smooth it out ---> charges when voltage is increasing, at maximum when voltage reaches peak ---> when voltage falls, capacitor discharges ---> keeps the ripple smaller ---> smooths out voltage
5. Good luck everyone
6. Hopefully it will be like the chemistry paper - only needing basic concepts and only applying them

Ryan
7. (Original post by L'Evil Fish)
AC ---> Step Down Transformer ---> Less Rings on Secondary ---> Diode Bridge Circuit used to create DC electricity ---> Diodes reverse bias dictates a flow that always has output voltage ---> Capacitator used to smooth it out ---> charges when voltage is increasing, at maximum when voltage reaches peak ---> when voltage falls, capacitor discharges ---> keeps the ripple smaller ---> smooths out voltage
Correct
Correct
I'm screwed

Vin + (R2/(R1+R2))

Included?
9. (Original post by L'Evil Fish)
I'm screwed

Vin + (R2/(R1+R2))

Included?
Not in the specimen, so possibly not in the real exam

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10. Good luck everyone

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11. (Original post by BP_Tranquility)
Not in the specimen, so possibly not in the real exam

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Great-.- thanks anyway

Good luck
12. (Original post by BP_Tranquility)
Good luck everyone

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I'm gonna need it, I only know p4

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13. Wow. Hardest exam I've ever been in. I'm supposed to be happy now, because my exams are over, but I'm not.
14. How did you all find it?
I thought it went quite well- there are a few questions that caught me out but overall, it wasn't too bad

What did you get on the question about parachutes? I got 56 for the first part but I wasn't too sure on the second part and got 24m

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15. (Original post by BP_Tranquility)
How did you all find it?
I thought it went quite well- there are a few questions that caught me out but overall, it wasn't too bad

What did you get on the question about parachutes? I got 56 for the first part but I wasn't too sure on the second part and got 24m

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I got 56 too, but for the second part I must have made a mistake as I got something like 120.
16. (Original post by BP_Tranquility)
How did you all find it?
I thought it went quite well- there are a few questions that caught me out but overall, it wasn't too bad

What did you get on the question about parachutes? I got 56 for the first part but I wasn't too sure on the second part and got 24m

Posted from TSR Mobile
It was much better than I thought it would be. I got 56 and then I got 160 or 180 - I can't remember which one
17. (Original post by BP_Tranquility)
How did you all find it?
I thought it went quite well- there are a few questions that caught me out but overall, it wasn't too bad

What did you get on the question about parachutes? I got 56 for the first part but I wasn't too sure on the second part and got 24m

Posted from TSR Mobile
I thought it was much easier than the specimen overall I think chemistry was easiest and biology was hardest, what about you?
Yeah I got 56 for part A then somehow 36 for part B however I never really understood those motion equations lol so hopefully I get at least 2 marks for it what outputs did you put for the logic gates? I got 0010
18. .what was that bridge rectifier circuit actually asking for? I did the process from + and back to - again for each?

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19. (Original post by BP_Tranquility)
How did you all find it?
I thought it went quite well- there are a few questions that caught me out but overall, it wasn't too bad

What did you get on the question about parachutes? I got 56 for the first part but I wasn't too sure on the second part and got 24m

Posted from TSR Mobile
Wasn't it 56 to 4 m/s over 6 seconds?

I got something in the hundreds which I thought made sense?

I'm pretty sure it was something like this (180m):

http://www.wolframalpha.com/input/?i...y%2C+6+seconds
20. (Original post by cameron262)
Wasn't it 56 to 4 m/s over 6 seconds?

I got something in the hundreds which I thought made sense?

I'm pretty sure it was something like this (180m):

http://www.wolframalpha.com/input/?i...y%2C+6+seconds
Well, the first part of the question said you had to find the distance travelled in 7 seconds (I think), but for the second part, it didn't say how long after the 7 seconds, he opened the parachute...So I just did speed=distance/time to work it out

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