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June 2011 G485-Fields, Particles and Frontiers of Physics

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Reply 880
Avatar for anshul96
anshul96
Original post by In the looney bin

Time taken for electron to reach point P = 1x10^-9 seconds.
P.D Across 150 micro-farad capacitor = 1.5.
Charge across 150 micro-farad capacitor like 2.25*10^-4 or something.

Same!

Original post by In the looney bin

Angle in Q4 = 18.8 degrees.

I must've rounded down, i put 18 degrees ;o

Original post by In the looney bin

Force (upwards) caused by magnetic field = 0.016N.
New reading on the balance scales = (2.5-0.016) = 2.484 N.

I got upwards too! And yeah, same for that...

Original post by In the looney bin

Hubble constant was like 2x10^-18 seconds^-1
Critical density of universe like 2x10^-27.


Hubble yes, critical density no...i got 7.89 x 10^-27
Original post by Oh my Ms. Coffey
Also how many of you missed the back page out :wink:


I did this with Newtonian world in January, dropping me to a B :frown:

MADE EXTRA SURE i looked this time, and enjoyed an easy 7 marks on fission :tongue:
Original post by In the looney bin
Switch was closed yes, force depends on wether the current was going clockwise (which would make it upwards) or anti-clockwise (which would make it downwards).


And the conventional current was going anticlockwise. It must be downwards.
Am I the only one disappointed with the lack of Quarks/Fundamental particles.
Original post by In the looney bin
Answers i remember:

Time taken for electron to reach point P = 1x10^-9 seconds.
P.D Across 150 micro-farad capacitor = 1.5.
Charge across 150 micro-farad capacitor like 2.25*10^-4 or something.
Ratio of capacitors i got 1/27 = 0.037. (I believe this to be wrong)

Angle in Q4 = 18.8 degrees.

Force (upwards) caused by magnetic field = 0.016N.
New reading on the balance scales = (2.5-0.016) = 2.484 N.

Hubble constant was like 2x10^-18 seconds^-1
Critical density of universe like 2x10^-27.

Density of uranium nucleus was large, cant remember what, my assumption was no seperation distance between nucleons.

Quote/reply if you disagree/agree with any and post what you remember!


Want the critical density like 7.26^-27?

And my assumption was treating the nucleus as a perfect sphere
Original post by Oh my Ms. Coffey
My assumption was the nucleon was treated as a sphere for volume.


this.
Original post by anshul96


Hubble yes, critical density no...i got 7.89 x 10^-27


Couldnt remember the number i got, rings a bell of 7. something, but i just knew it was right when order of magnitude was -27.
Reply 887
Avatar for scotzbhoy
scotzbhoy
Thought that went pretty well, though the electrons through charged parallel plates questions was horrible!
For the question with the rod and the balance, the force was downwards. LHR should have been used, it was a motor not a generator.
Reply 888
Avatar for anshul96
anshul96
Original post by rudebwoi93
this.


omg omg dipzzzyyy!!
Reply 889
Avatar for Pheylan
Pheylan
The number of turns on the secondary coil wasn't an integer - wtf?
Original post by fwed1
oh well I put downwards and added the force :P maybe i'll get ecf


I figured out that downwards is correct. Sorry about that cos few people in my class thought it was upwards.
Original post by cleverbong
I figured out that downwards is correct. Sorry about that cos few people in my class thought it was upwards.


Thanks for leading me onto a nervous breakdown!
Reply 892
Avatar for ChoYunEL
ChoYunEL
1
Alpha Scattering Particle Experiment
-So annoyed I forgot the fundamental forces ¬_¬

PET - Woo!
Nuclear reactor - Double woo!

Hardest probably was finding the charge at the midpoint of the thing...
F/Q = V/D
-4NC +5NC - Distance of 3.2x10-2?
Original post by Pheylan
The number of turns on the secondary coil wasn't an integer - wtf?


I got like 20something.something
(edited 12 years ago)
Reply 894
Avatar for ChoYunEL
ChoYunEL
1
Original post by Pheylan
The number of turns on the secondary coil wasn't an integer - wtf?


Yeah... that annoyed me - I rounded up to 220 lol
Reply 895
Avatar for Pheylan
Pheylan
Original post by ChoYunEL
Yeah... that annoyed me - I rounded up to 220 lol


Same, is that another mistake by OCR?
Original post by ChoYunEL
Yeah... that annoyed me - I rounded up to 220 lol


I got 219.23 I think so kept it at 219. It was an annoying question as I was expecting an outright number.
Reply 897
Avatar for ewen1605
ewen1605
7
Mistakes in the written questions of exam papers are simply inexcusable, especially when its something so obvious.

The diagram for the electron question said the separation of the plates was 0.05 m, but the question gave 0.05 cm.

With all the "checking and rechecking and proofreading" they claim to do, how are mistakes like this left in the exam paper?

Wasn't a bad paper overall. Quite pleased.
Original post by Pheylan
The number of turns on the secondary coil wasn't an integer - wtf?


Think i got 219.2

left it as 219.
Reply 899
Avatar for anshul96
anshul96
Original post by Pheylan
Same, is that another mistake by OCR?


No, it's allowed to be non-integer, that's because the values used in calculating the value were not given to a great deal of accuracy.

The only mistake I spotted was the 0.05m/0.05cm thing..

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