Physics Answers

[fkzbaby]

i got for multi choice:
B B B C B B C C C C A A D (sound)
my mate got the same except his 12. was B (hes smartest person ever btw lol)

[onlyfknhuman]

I got DBCCCBBCCACCA for the Photonics questions

I'm pretty sure I got Q->P for the square coil thingo question too - definitely wrote clockwise, can't remember which way around that was though  :idiot2:

for the Vrms question

4 over sqroot 2 same here

[champorado]

That fountain question seemed weird. It seemed like something you'd get in Unit 3.

Did you have to have the rms voltage as an exact value? I think i wrote 2.83 or something.

[Tea.bag]

wtf i got 8 Volts cause i found the power loss and then i think its 32=4*V

[onlyfknhuman]

That fountain question seemed weird. It seemed like something you'd get in Unit 3.

Did you have to have the rms voltage as an exact value? I think i wrote 2.83 or something.

I PUT 2.8v

[onlyfknhuman]

I think it was a little harder than last year on a few q's, but mostly easier. Longer too?
Lets begin...  8-)

Magnets & Stuff
--------------------
1. Use rh grip rule, current flowing anti-clockwise

X. Coil leaving Field:
change in flux = final flux - initial flux = zero - into page = out of page. According to lenz law, this change is opposed, hence field set up into page. Via rh grip rule, current flows clockwise, from (p/q I cant remember) to (p/q). Q-P (Clockwise) (unsure-> need mao or someone to confirm. )

X.Vrms = Vp-p ÷ 2 ÷root(2) (I cant do latex :-( )
8÷2÷root(2) = 2.8V



X Power of spotlight over fountain = 48W
X. Voltage over globe 9v
X. Current in circuit = (0.5Ω*2 + 3Ω÷2 = 2.5Ω therefore 12/2.5 =) 4.8A
X. Power = v^2/R = 40W
X. *V
X. Current at primary = 0.167A
X. 400 turns



Light & Matter & Stuff
------------------------
X. 0.0364nm
X. 97nm
X. h = 5x10^-15 evs
X. 3.03
X. 2.4ev
X. Arrow from n=4 (12. to n=2 (10.6) with head at 2
X. Jump from 12.8 -> 0 = max energy = max freq = min wavelength

Photonics & Stuff
--------------------

Syncrotron & Stuff
---------------------

Sound & Stuff
-----------------
1.B
2.B
3.B
4.C
5.B
6.B
7.C (B?)
8.C
9.C (B?)
10.C
11.A (D?)
12.B (C,A?)
13.C (B,D?)

:-) hope you physicists went well.


~pinchies

(Thanks to onlyfknhuman, BiGDaN, , , , for some I cant remember)

got exactly the same except for. that gay q to p shit dammit, ur prob right.

and for sound Q 12. definitly the hardest. i put C however :S was juggling between B and C

i assumed that, since their were 3 options for 1. and otpion 2 didnt work. i thought it shouldve worked, =p

[fkzbaby]

the fountain question was easy?
Total resistance is 3 ohms plus 1 ohm ( bulb + wires )
knowing V=IR
Bulb has 3 x the resistance of the wires therefore 3x the voltage.

so voltage over bulb = 3/4 X 12
= 9V

[Quickclaw]

I got DBCCCBBCCACCA for the Photonics questions

I'm pretty sure I got Q->P for the square coil thingo question too - definitely wrote clockwise, can't remember which way around that was though  :idiot2:

for the Vrms question

No simplifying?

[pinchies]

I put [8] [÷] [2] [root] [2] into my casio fx-82, and it spits out 5.66, and I didn't do a reality check. eeek!

[champorado]

you should have had 2 root 2 in brackets. what you did was 8 divided by 2 times root 2.

[Skullmaster4]

Mao told me after the exam it was Q-P

I spent like 10 minutes on it and went with P-Q, hope Mao's wrong!

[champorado]

I hope he's not. That's what I got. I had something like the induced current produces a downwards field.

someone post the exam already! i'm dying here.

[fkzbaby]

whichever one was at the top was where the current started
coz change in flux was upwards, lenzs law gives negative so its back thru the loop (same way as mag field lines)
then RHG rule

[champorado]

so did it flow clockwise or anticlockwise?

[lacoste]

should i do physics 3/4 next year?

physics seem incredibly hard with all the maths work? is the math work difficult;are they like formulas ..?