CIE physics

[falafail]

in the syllabus it says, "show an undrstanding of the existence of discrete electron energy levels in isolated atoms and deduce how this leads to spectral lines"

are spectral lines produced when an excited electron goes back to its ground state? because it emits photons? is that it?  

[~ A.F ~]

Yuo thats kinda true..visit http://www.s-cool.co.uk/alevel/physics.html  for more details and animations

[falafail]

Yuo thats kinda true..visit http://www.s-cool.co.uk/alevel/physics.html  for more details and animations

"The lines on the spectra are the frequencies of light that exactly match the energy required to make the jumps between energy levels."
right now i'm confused.
are the lines caused by the emission of photons, or the absence of those particular frequencies of light? can someone please explain this?

[astarmathsandphysics]

There is a page on my website. Will post the link when I get home

[T.Q]

"The lines on the spectra are the frequencies of light that exactly match the energy required to make the jumps between energy levels."
right now i'm confused.
are the lines caused by the emission of photons, or the absence of those particular frequencies of light? can someone please explain this?

check this http://physics-edu.org/line_spectrum_of_hydrogen_atom.htm

[falafail]

nevermind, got it. thanks anyway.

there's something else i don't get though...
show an understanding of how the force on a current-carrying conductor can be used to measure the flux density of a magnetic field using a current balance  

[astarmathsandphysics]

A hall probe is easier to use. I am looking for a simple explanation of how current balances work. I dont understand at the moment why it doesnt work the same as a dynamo

[astarmathsandphysics]

http://images.google.co.uk/imgres?imgurl=http://cla.sd57.bc.ca/~rgiroday/Physics12.0809/unit7/U07L04/currentbalance1.gif&imgrefurl=http://cla.sd57.bc.ca/~rgiroday/Physics12.0809/unit7/U07L04.htm&usg=__75ckyJLYFaW03JyEISNFwrylfj0=&h=415&w=548&sz=16&hl=en&start=1&sig2=T7w9-HUDrwP9btU0IWxc5g&um=1&itbs=1&tbnid=wHIm-mKtLEKpZM:&tbnh=101&tbnw=133&prev=/images%3Fq%3Dmeasuring%2Bmagnetic%2Bfield%2Busing%2Bcurrent%2Bbalance%26um%3D1%26hl%3Den%26client%3Dsafari%26rls%3Den-gb%26tbs%3Disch:1&ei=lRHUS80GyZM4kv2x0w0


expained here

[falafail]

A hall probe is easier to use. I am looking for a simple explanation of how current balances work. I dont understand at the moment why it doesnt work the same as a dynamo

what's a dynamo?
and could you explain how hall probes are used as well? please & thank you.

[astarmathsandphysics]

A dynamo is just a wire loop that turns in side a magnetic field and so generates a current.
A hall probe measures a magnetic field by measuring the force on a current carrying conductor in a magnetic field

[dodo]

please check may/june 2009 CIE physics AS unit 2
question number 5 b)
please i need the reply as soon as possible
and if please with the explanation how u got the answer

[nid404]

I do cie so i don't have the paper...and i find it diff to figure on freeexampapers...
it'll be gr8 if you can upload it

[astarmathsandphysics]

Do you mean paper 2