General Thoughts: Physics (3 Viewers)

[keith1234]

I do 13 units, and I knew as I walked in that physics wasn't going to count ever since term 1. Chemistry had just finished and I already was in post HSC mood afterwards. So I did minimal study, and everything that I didn't study for was asked in the exam. Calculations I could do, but the theory (esp in quanta to quarks screwed me over so bad. I probably got 5 in that section.) I'm estimating a raw of 60. Right now, I don't really care because it won't affect my atar at all, but if you're reading this and you're just starting year 12, drop a subject if you know that it wont count overall (but only if you do 12 or more units ofc.) Otherwise, you feel like youve wasted a year on a subject, where you could be better off doing other subjects or socialising in free periods. Also, I went tutoring for phys too, now I feel guilty that I wasted money. Will make it up by paying my parents back the cost of the phys tuition for the year (Y).
And thats the end of my story

 

[anomalousdecay]

I assume that you may lose 2 or 3marks since the question said "changing electrical properties of materialS" so you had to talk about two materials.
For superconductors would you say something like; superconductors below their critical temperature will have zero resistance as electrons form cooper pairs. This led to use in maglev trains (outline benefits) and short distance electrical transmission (outline benefits).

That's pretty much cause, effect, reason for superconductors. Need reason for maglev: Meissner effect.

 

[Fizzy_Cyst]

The head of James Ruse Science confirmed that the solar cell can be used in the description of the photocell. Since she said the solar cell is a type of photocell.

Unless she is in the group of teachers who come up with the marking scheme for the question, her 'confirmation' means diddly squat!

In terms of the syllabus, photocells and solar cells are two COMPLETELY different dot points, in two COMPLETELY different sections.

Whenever the word photocell or photoelectric cell has been used in HSC previously, it has been referring to the anode / cathode arrangement. A solar cell has never been referred to as a photocell previously.

I can see the arguments for either side, but i would put my money on them saying anode / cathode arrangement is a photocell. I suppose we need to wait til the marking guidelines are released!

 

[Menomaths]

That's pretty much cause, effect, reason for superconductors. Need reason for maglev: Meissner effect.

I'm pretty sure the Meissner effect isn't used in Maglev?

 

[cyradis]

gosh astrophysics + photocell question just ruined it all. Anyone know how an 84-5 raw mark would scale?

 

[Randox]

No its not. Pretty sure you lose a mark for saying it is.

 

[Randox]

What was everyone explanation for motor propelling vehicle. Just motor effect, torque, rotation of coil, propels vehicle?

 

[cyradis]

What was everyone explanation for motor propelling vehicle. Just motor effect, torque, rotation of coil, propels vehicle?

Yup thats what i said

 

[anomalousdecay]

I'm pretty sure the Meissner effect isn't used in Maglev?

Wait what? Now I'm just confused.

 

[Randox]

Wait what? Now I'm just confused.

Meissner effect shouldn't really be in the course... but anyway...
Maglev train just uses the repulsive force between two superconducting magents too stay off the ground and levitate. Propulsion is achieved by having magnets on the side of the track which attract the train. Obviously this is simplified a lot

 

[anomalousdecay]

Unless she is in the group of teachers who come up with the marking scheme for the question, her 'confirmation' means diddly squat!

In terms of the syllabus, photocells and solar cells are two COMPLETELY different dot points, in two COMPLETELY different sections.

Whenever the word photocell or photoelectric cell has been used in HSC previously, it has been referring to the anode / cathode arrangement. A solar cell has never been referred to as a photocell previously.

I can see the arguments for either side, but i would put my money on them saying anode / cathode arrangement is a photocell. I suppose we need to wait til the marking guidelines are released!

Everyone, Fizzy Cyst is right.

I think what we really missed out on the relation that a solar cell can be a photocell as long as the fact that n-type can act as a cathode and p-type can act as the anode.

But to make this a valve, You can not use a depletion layer. Instead, there should be a physical gap.
Cause I didn't state this, I'd probably only get a 3 max/5, unless they decide to include solar cells and are nice.
That is what occurs in LEDs in Silicon Age at least.

Correct me if I'm wrong Fizzy. I pretty much am these days with Physics.

 

[khoavo12]

I think Maglev train does use the Meissner effect

 

[anomalousdecay]

Did anyone get the photocell one absolutely perfect???

 

[panda15]

Did anyone get the photocell one absolutely perfect???

I mixed up the anode and the cathode. Why can't they just be the same thing in physics and chemistry?

 

[anomalousdecay]

I mixed up the anode and the cathode. Why can't they just be the same thing in physics and chemistry?

I thought that as well at first. Just remember that they are reversed.

Far-out I could have used my LED logic to fix up my answer.

 

[Menomaths]

I think Maglev train does use the Meissner effect

It doesn't as far as I know, might be wrong though.

 

[Randox]

So according to physics in focus... they are used to activate alarms and automatic doors. Is this correct? Just hoping I can get 1/5 considering I wrote all the lines. Didn't do a diagram though...

 

[Menomaths]

So according to physics in focus... they are used to activate alarms and automatic doors. Is this correct? Just hoping I can get 1/5 considering I wrote all the lines. Didn't do a diagram though...

They are, but the question didn't ask for their uses

 

[Randox]

They are, but the question didn't ask for their uses

Lol. Would their be a mark for saying. "The photoelectric effect is the basis for its operation. The photoelectric effect is..."?
Btw would the diagram be 1 or 2 of the 5 marks?

 

[Menomaths]

Lol. Would their be a mark for saying. "The photoelectric effect is the basis for its operation. The photoelectric effect is..."?
Btw would the diagram be 1 or 2 of the 5 marks?

I honestly have no idea lol but for saying photoelectric effect you might get 1

My guess is diagram is 2 marks