Physics Unit 4 Exam discussion

[ngRISING]

whats diffraction?

[NE2000]

Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"

That should be ok. I'm worried about drawing loops lol, I don't think you've got anything to worry about

[scope9]

Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"

itute says loops so i suppose loops will be fine!

whats diffraction?

did you even do physics? haha. just kidding
its the bending of light as it passes through a gap. the amount of diffraction depends on the wavelength:gap ratio. or something like that.

[metalvalour]

Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"

did exactly what you did. but itute's one doesnt have the 2 lines (not loops)?!

[wilfred]

can any one help me with this from photonics
question 2
Which one of the following statements best describe the production of light in an incandescent light bulb?
I know its between
C.Acceleration of electron in random thermal collisions
D. Emission of electromagnetic radiation (light) by electrons accelerated by the applied voltage
which one is it? and why is it not the other one?
thanks heaps

[mark_alec]

It is C. An incandescent light bulb produces light because the tungsten filament is very hot. This means that the electrons are accelerated in 'random' collisions.

For D, that would be an example of synchrotron light, as it is caused by the acceleration of electrons in an electric field.

[majo]

TrueTears id like to sincerely thankyou for providing us with that cheat sheet. Im pretty sure it has gotten me an A-A+, i cant find any errors. Does anyone know what a B+ and a high A would get me in terms of SS?

i am also curious

high B and a A+/high A

?

[ayaz]

So I think I might have stuffed up the question on the exam that asks you to calculate W.

I used W = hf "zero"

But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV

Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?

i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....

do you think i could get the marks (3marks)

[crappy]

So I think I might have stuffed up the question on the exam that asks you to calculate W.

I used W = hf "zero"

But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV

Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?

i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....

do you think i could get the marks (3marks)

you might get the marks, If its asking for the work function then all you had to was read off the graph( the y intercept). I cant really remember but, you didn't really need to work out anything for that question, besides reading the graph.

[methodsboy]

So I think I might have stuffed up the question on the exam that asks you to calculate W.

I used W = hf "zero"

But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV

Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?

i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....

do you think i could get the marks (3marks)

OMG dude get over it! it happened all most a week ago... cease with the futile lamenting