OCR PHYSICS B G495~ 18th June 2015 AM ~ A2 Physics

Original post by h4mz4

How do u work out wavelength of electron if u have h-6.6*10^-34 m- 9.1*10^-31 and also KE 2*10^-18

Thanks

use K.E=1/2*m*v^2 and wavelength = h/p = h/mv to work out wavelength as = 0.35nm

Reply 165

STATER

Original post by smerkz

It does indeed, yes :smile:

One last question. In line 56 of the pre release, it says that xrays are produced. It's because the incoming electron transfers energy to the stationary electron which then rises to a higher energy level. But what causes it to fall back down to emit the X ray?

Reply 166

Tibbz2

13

Original post by urz13

How on earth do you calculate the emf from the gradient of the graph in Q11 part b) here?

Paper: http://moodle.flintshire.gov.uk/hhs/pluginfile.php/2360/mod_folder/content/0/Current%20Syllabus/G495%20June%2014.pdf?forcedownload=1
(June 2014 paper)

Thanks!

Do you have a mark scheme for june 2014??

Reply 167

OP

Original post by Iridann

use 1/2 * mv^2 = hc/lambda

Isn't that what I said? :wink:

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Reply 168

OP

Original post by HennersPD

use K.E=1/2*m*v^2 and wavelength = h/p = h/mv to work out wavelength as = 0.35nm

Why can't you use E=hc/lamda?

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Reply 169

HennersPD

Original post by Mutleybm1996

Why can't you use E=hc/lamda?

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thats the same just written differently haha! either way works just fine! how're you feeling for this, did you find g494 good? :smile:

Reply 170

OP

Original post by HennersPD

thats the same just written differently haha! either way works just fine! how're you feeling for this, did you find g494 good? :smile:

Weird
I get 9.9x10^-8
When I use E=hc/lambda

Assuming E is 2x10^-18

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Reply 171

OP

Original post by HennersPD

thats the same just written differently haha! either way works just fine! how're you feeling for this, did you find g494 good? :smile:

I made some silly mistakes
Not sure how many marks I lost
Quite a few on silly mistakes
Hopefully I got an A
I just need an A in this to be safe

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Reply 172

francescafisher

I thought you could have two electrons at any energy level at a time... But a maximum of two

Reply 173

STATER

Original post by francescafisher

I thought you could have two electrons at any energy level at a time... But a maximum of two

I think thats only the case in the first energy level and its something to do with spin that we don't need to know.

Reply 174

G_Parv

Can anyone help me with re-arranging the relativistic factor equation to find velocity when you have the relativistic factor?
I'm wracking my brains to do it but I just can't get the right answer. :frown:

Reply 175

urz13

8

Original post by Tibbz2

Do you have a mark scheme for june 2014??

Here you are :smile:

(hopefully this link works, if not theres a link to all past papers and markschemes on P1 or 2 of this thread)
file:///C:/Users/Alex/Downloads/G495%20June%2014%20Mark%20Scheme%20(3).pdf

Reply 176

username1200599

12

Original post by urz13

Here you are :smile:

(hopefully this link works, if not theres a link to all past papers and markschemes on P1 or 2 of this thread)
file:///C:/Users/Alex/Downloads/G495%20June%2014%20Mark%20Scheme%20(3).pdf

That would be the local directory :P

Reply 177

maxAmain

can anyone tell me everything I need to know about bosons please? Read this https://en.wikibooks.org/wiki/A-level_Physics_(Advancing_Physics)/Bosons it didn't help. In particular I don't get the weak nuclear force, thanks

Reply 178

OP