Help needed for Edexcel Physics Unit 2!!

OP

So gas chamber is actually the same as cloud chamber?

Let me summarise this and see if it's correct:

For bubble chamber, the liquid hydrogen is ionised by the ion on which bubble forms and gives a track when a photograph is taken as the light is reflected back.

For cloud/gas chamber, the air is ionised on which the alcohol or gas condenses, leaving a trail.

Right?

Reply 22

~Adel~

I feel like kissing you, discombob!!!

Hahaha thanks :biggrin:

, but I think that won't be necessary Adel hahah.

~Adel~

I know how hydrogen bubble chamber works, but what about spark drift chamber? The explanation in the text book is rather vague..it only says when the ion moves through the wires it ionises the air or something and hence a current is produced..

It's basically a chamber of gaseous particles, and when the particle moves through the gas it ionises it. There is a pattern of evenly spaced conducting lines placed in the gas, so when a particle is ionised it immediately jumps across a pair of the conducting lines, producing a spark. A computer can be used to piece together the series of sparks, resulting in a visualisation of the track of the particle. Kinda dodgy lol.

~Adel~

I've not learned gas chamber..how does it work?

It's very similar to the bubble chamber, except this time you have alcohol vapour. When the particle passes through it ionises the gas molecules, resulting in condensation of the liquid alcohol. This can be illuminated, revealing the path.

~Adel~

Do we need to mention when the ion moves into the bubble chamber, the pressure drops drastically and the produce supersaturated hydrogen liquid?(it was given in the mark scheme for a question on bubble chamber..)

I don't know about the pressure changes, but the markscheme can be dubious, so I would mention all the details possible. I remember in one paper there was a mark for saying that the hydrogen bubbles would be illuminated to be seen... :s-smilie:

damn Edexcel lol.

Reply 23

myxm7

yep, although im SURE we're really only needed to explain one of them. looking at my notes ive only really made detailed notes on one detector.

EDIT: yep to add to what discombob said marks are given for correct and relevant physics in those questions.

Reply 24

OP

I think you were looking at the same question as i did..it says the bubbles will reflect the light and consequently the white track can be seen. LOL!

Regarding the spark chamber: Why does the ionised gaseous atom jump across the conducting line? What causes it to ''jump''?

Reply 25

~Adel~

I think you were looking at the same question as i did..it says the bubbles will reflect the light and as a consequently the white track can be seen. LOL!

Hahaha yeah I think so too :p:

~Adel~

Regarding the spark chamber: Why does the ionised gaseous atom jump across the conducting line? What causes it to ''jump''?

Sorry, I forgot to mention that there's a high potential difference between the conducting wires :rolleyes:

Reply 26

Dragonfly07

18

Wish I did physics instead of Biology. :s

Reply 27

OP

Why? Given a chance i'd choose Biology over Physics, DEFINITELY.

Oh, that cleared my doubt, discombob! Wow..i can't imagine i managed to get such a great person to help me! Are you sitting for Unit 6 tomorrow, discombob?

Reply 28

~Adel~

Why? Given a chance i'd choose Biology over Physics, DEFINITELY.

Oh, that cleared my doubt, discombob! Wow..i can't imagine i managed to get such a great person to help me! Are you sitting for Unit 6 tomorrow, discombob?

Hahah yeaaapp sitting Unit 6 tomorrow...feeling absolutely doomed :eek:

. The randomness of this module kills.

Reply 29

OP

I agree with your rant on Biology questions' ambiguity..but anyway, you won't go too far from an A if you do know your stuff well. The worst that could happen is ended up with a low A. (which is also quite sad to be honest, considering we've spent so much time learning and memorising it)

I'm quite sure discombob is going to score 120/120 in Unit 6 tomorrow..he really sounds like he's going to.(and i think he will be scoring that too, he has my blessing for being such a helpful person.=)

Reply 30

Havokiba

Biology exams are really ambiguously worded :frown:

Hard to know if you've done very well on them; even if you have the knowledge, usually the mark scheme asks for the most blatent points ever even if it seems so obvious to you that you assume the question implies it... Urgh. Minor rant there :P

On the other hand, Biology has much nicer stuff to remember. With Physics, you can work out a lot of things using what you do know, but some of the things you do really have to know are so awkward & hard to remember.

So true...I hope I hedge my bets well with the bio synoptic day after tomorrow! :s-smilie:

Havokiba

On another note, I understand that Van de Graff generators produce the particles sent as a drift beam into linacs or into cyclotrons/synchrotrons etc but I'm not sure exactly how? Anyone know?

All I know is that the belt creates a large potential difference between the dome and another object that can be connected to the ground wire. The electrons can then produce a spark if the p.d. is big enough...but I'm not too sure how that links in with accelerators, I guess it just accelerates the electron across that gap (which could be linked to the start of a linac or something)?

Reply 31