OCR Physics A G485 - Frontiers of Physics - 18th June 2015

lmao i defined what electric field strength is not explain what an electric field is

oh well i think i got an A still and no more physics ever again

finally done with this crap and i can throw all my notes and books away now

don't really care about what marks i get now tbh

Reply 1701

MO2898

7

Original post by ETRC

lmao i defined what electric field strength is not explain what an electric field is

oh well i think i got an A still and no more physics ever again

finally done with this crap and i can throw all my notes and books away now

don't really care about what marks i get now tbh

Oh yeah that was weird!
Not sure if 'E fields arise as a result of charged objects and can exert forces on other charged objects' will do the job

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Reply 1702

TiiMMYz

1

Original post by Lousamnap

What don't you get!!! ostri and physics DONT MIX!!!!

Did you not do the g481 mechanics paper last year? :wink:

Reply 1703

MO2898

7

Original post by rosstoal

With the rate of temperature rise, I'm sure you had to minus 273 degrees. As it asked for it in Celsius, and specific heat capacity is joules per kelvin
I got it to be in the 300s

Nope. The energy required to raise temp by one kelvin or degree C for a given mass of a given material is the same. Hence rate will be the same.

Reply 1704

matthew6665

2

Original post by L'Evil Fish

Because they need them for their offers...

Well I don't know which unis give such high offers.. 2 people I know are going Oxbridge and both have AAA offers :s So I guessed that ****ter unis will not have A* offers cause that's just mad.

Reply 1705

jcwh97

2

Original post by chem@uni

88 ish

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It won't be that high...

Reply 1706

Oraeng

9

On that first question about the electron entering the magnetic field, did people put the electron decelerated to rest then accelerated in the opposite direction out of the hole????
The electric field was opposing the motion of the electron right??

Reply 1707

Leechayy

13

Say, what did you guys do to find the current?

I ended up with a value to the -6 which seemed way too small.

I used f=1/t and Q=VC then found Q from exponential decay.
After I divided this by t for average current.

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Reply 1708

Genty Boy

3

Original post by Oraeng

On that first question about the electron entering the magnetic field, did people put the electron decelerated to rest then accelerated in the opposite direction out of the hole????
The electric field was opposing the motion of the electron right??

Yeah, I thought it just went back through the hole because the field and current were in the same direction, so motion would be opposing field direction.

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Reply 1709

Elcor

14

Original post by fatart123

Should be around 74 for an A and 80ish for an A*? Wasn't much written crap that gives people easy marks tbh

That's about average so probably, yeah. Average A is 83 of the newer papers.

Reply 1710

Oraeng

9

Original post by Genty Boy

Yeah, I thought it just went back through the hole because the field and current were in the same direction, so motion would be opposing field direction.

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Ooo good!

Reply 1711

SH0405

15

Original post by leroythelost

I love how you said that just after I finished working out I got about 78 in this paper..Thank anyway.

How did you work that out?

Reply 1712

MO2898

7

Original post by Oraeng

On that first question about the electron entering the magnetic field, did people put the electron decelerated to rest then accelerated in the opposite direction out of the hole????
The electric field was opposing the motion of the electron right??

Yeah, I said it will definitely decelerate, but whether it stops and reverses is down to the strength of the electric field as they didn't give us any explicit values of that, or not that I can remember anyway.

Reply 1713

The Room Student

2

Pretty nice paper I thought. I liked the star-ratio questions. Everything seemed fair enough.

Little gutted about multiplying by 0.01 instead of 0.99 on the heat change question though. Ah well. Exams are over! :biggrin:

Reply 1714

Leechayy

13

Original post by Genty Boy

Yeah, I thought it just went back through the hole because the field and current were in the same direction, so motion would be opposing field direction.

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Surely that only applies for magnetic fields? It was an electric field so don't you mention it accelerating to 24eV?

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Reply 1715

Leechayy

13

Original post by The Room Student

Pretty nice paper I thought. I liked the star-ratio questions. Everything seemed

Little gutted about multiplying by 0.01 instead of 0.99 on the heat change question though. Ah well. Exams are over! :biggrin:

You do?

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Reply 1716

L'Evil Fish

OP

18

Original post by matthew6665

Well I don't know which unis give such high offers.. 2 people I know are going Oxbridge and both have AAA offers :s So I guessed that ****ter unis will not have A* offers cause that's just mad.

Those are humanities at Oxford.

Cambridge offers are A*A*A for sciences

And somehow I don't think Cambridge is ****ter

Manchester Physics A*A*A

Cambridge, Imperial, Warwick, Manchester all give higher offers

Reply 1717

kateyl

3

Original post by yfp786

it said intensity passing through NOT reflected, so you must minus the reflected percentage (36) from full percentage (100) to get intensity passing through