General Thoughts: Physics (2 Viewers)

[panda15]

Any idea which ones I've got wrong then? I'm curious, I was sure I got 17/20 comparing to other peoples answers lol.

I counted you had 5 wrong

1, 13, 15, 16 and 20.

 

[RealiseNothing]

I counted you had 5 wrong

1, 13, 15, 16 and 20.

17 too.

 

[MATHmaster]

Oh please be true.

This is where I got my information from. I can't believe photocells apparently involve the cathode ray tube. Both answers are correct imo. And if a reliable source like Jacaranda is wrong, the HSC markers should accept both answers

 

[namelyanonymous]

I drew a solar cell for the photocell question I was really blanked out so I couldn't decide between photomultiplier and a solar cell

I went out and all my friends said they did photomultipliers do you think I'd lose all 5 marks?????

In other news FINSIHED MY HSC WOO

 

[Ozzyy]

1, 13, 15, 16, 17, 20.

Dammit :c Is 17 because of back emf? ;x

 

[pls]

since the mass moves at constant felocity net force is O. this means the upward force produced by the motor's rotation should equal the downward weight force of the mass.
so use f=mg

yeah thats what i did. Just totally forgot that w=mg is actually f=ma,

 

[panda15]

17 too.

I'm not completely sure what the answer is, so I left it out.

 

[RealiseNothing]

Dammit :c Is 17 because of back emf? ;x

Yep back EMF decreases current, it's D

 

[Fizzy_Cyst]

This is what the Jacaranda textbook says about photocells, why are solar cells wrong to mention?

A photocell is a device that uses the photoelectric effect. These devices include photovoltaic, or solar cells, which convert electromagnetic energy, such as sunlight, into electrical energy. Other examples are photoconductive cells and phototubes.

pg 207

Someone explain why drawing a solar cell is wrong?

Look in the syllabus. They differentiate between solar cells and photocells

Identify data sources gather, process and present information to summarise the use of the photoelectric effect in:
- Solar Cells
- Photocells

 

[Ozzyy]

Yep back EMF decreases current, it's D

Ahh well, guess I'm knocked down to 80s raw because of that lame photocell question x.x Good enough for me, still band 6 I think. :x

 

[Randox]

LOL what did everyone have for qn 26? a and b

 

[hjed]

Overall pretty good.

Medical Physics questions where very different than previous years, which made it harder for me. No calculations in it which was annoying, I ended up having to get extra booklets for both of the medical physics booklets.

I couldn't remember enough detail about photocells so I talked about solarcells with a heavy focus on how the photoelectric effect works. Hopefully that'll let me access some marks? BTW Jacaranda is pretty unclear on the topic so fingers crossed they let it through, but I suspect not

Also did people talk about semi or superconductors for the changing electric properties of materials? I focused on semiconductors as I'm pretty sure that's what the dot point is on, but briefly talked about superconductors as well. (went right down to the bottom of the page, hope they don't get annoyed about that.)

BTW with the first question, did anyone else find that they had to draw a line of best fit for the graph as the points didn't fit on a straight line?

 

[Fizzy_Cyst]

You should NEVER rely on one source for your information!

Always access 3 textbooks!

 

[joshyoshieee]

Oh please be true.

+1

 

[superSAIyan2]

LOL what did everyone have for qn 26? a and b

i wrote
V=Ed = 0.01 x 15 = 0.15 V

b)magnetic field deflects electron down. so electric field must deflect it up. so direction of field is down.
Equate forces caused by electric and magnetic field; Eq=qvB
E = 10^4 x 0.5 = 5000 N/C downwards

 

[Kamiyochama]

Was happy with the calculations and long responses to some extent.

Astrophysics on the other hand was mental.

Astro, i completely agree.

 

[Ozzyy]

LOL what did everyone have for qn 26? a and b

I think I got 0.15 for a (E=v/d so v=ed) and for b I think i got 5000Vm (qvb=eq so e=vb) I could be wrong though

Overall pretty good.

Medical Physics questions where very different than previous years, which made it harder for me. No calculations in it which was annoying, I ended up having to get extra booklets for both of the medical physics booklets.

I couldn't remember enough detail about photocells so I talked about solarcells with a heavy focus on how the photoelectric effect works. Hopefully that'll let me access some marks? BTW Jacaranda is pretty unclear on the topic so fingers crossed they let it through, but I suspect not

Also did people talk about semi or superconductors for the changing electric properties of materials? I focused on semiconductors as I'm pretty sure that's what the dot point is on, but briefly talked about superconductors as well. (went right down to the bottom of the page, hope they don't get annoyed about that.)

BTW with the first question, did anyone else find that they had to draw a line of best fit for the graph as the points didn't fit on a straight line?

I spoke about both superconductors (maglev train and mri) and semiconductors (solid state devices and solar cells) and linked their use to society x.x and I drew a line of best fit lightly, It didn't say you had to but i did it anyway just incase :s

 

[tutorhunt]

I think I got 0.15 for a (E=v/d so v=ed) and for b I think i got 5000Vm (qvb=eq so e=vb) I could be wrong though



I spoke about both superconductors (maglev train and mri) and semiconductors (solid state devices and solar cells) and linked their use to society x.x and I drew a line of best fit lightly, It didn't say you had to but i did it anyway just incase :s

I got 1.5 v as well, and 5000 v.m. I thnk you are correct

 

[Menomaths]

I think I got 0.15 for a (E=v/d so v=ed) and for b I think i got 5000Vm (qvb=eq so e=vb) I could be wrong though

Got this too

 

[superSAIyan2]

for the question where you had to draw the emf versus time, i drew the wrong graph at first. But then i crossed it out and drew a new graph with all the correct features. However i didnt use a ruler (i only realised 20seconds before end of exam), would this cost me a mark?