Full Examination Paper (2 Viewers)

ocatal

Active Member
Joined
Sep 1, 2012
Messages
298
Gender
Male
HSC
2013
Looking through my textbook. It says "A photocell is a device that uses the photoelectric effect. These devices include photovoltaic, or solar cells."
 
Joined
Oct 1, 2012
Messages
86
Gender
Male
HSC
2013
So ironic, I knew photocells perfectly but I crammed solar cells before the exam and I wrote about solar cells.
Good work Abdullah, good work...
 

Fizzy_Cyst

Owner @ Sigma Science + Phys Goat
Joined
Jan 14, 2011
Messages
1,212
Location
Parramatta, NSW
Gender
Male
HSC
2001
Uni Grad
2005
my teacher with a PHD said that it is... awks for you Meno.
Actually, pretty awks for your PhD teacher when he is incorrect.

Have a look at where that the dot point concerning photocells in the syllabus.. Before semiconductors..

Hmmmmmmm....

I wouldnt be surprised if they end up accepting both
 
Last edited:

Menomaths

Exaı̸̸̸̸̸̸̸̸lted Member
Joined
Jul 9, 2013
Messages
2,373
Gender
Male
HSC
2013
Looking through my textbook. It says "A photocell is a device that uses the photoelectric effect. These devices include photovoltaic, or solar cells."
Solar cells use the photoelectric effect, but they are different to photoelectric cells

For solar cells I recall, you have to get an electron from the n type side liberated and then it goes through some depletion zone then through an external circuit whereas photocells it's when an incident ray strikes the emitter and the electron that is liberated goes to the collector then through the external circuit or something like that
 

superSAIyan2

Member
Joined
Apr 18, 2012
Messages
320
Gender
Male
HSC
2013
basically i wrote: a photocell consists of an anode and a photosensitive cathode in a highly evacuated glass tube. When light of a frequency higher than the cathode's threshold frequency strikes the cathode it emits free electrons by the photoelectric effect. The electrons are accelerated as a focussed beam towards the positive anode due to a applied potential difference, this initiates a photocurrent. The current can be amplified to do work in an external circuit; e.g. power a lamp.

Isnt photocells easier than solar cells?
 

Menomaths

Exaı̸̸̸̸̸̸̸̸lted Member
Joined
Jul 9, 2013
Messages
2,373
Gender
Male
HSC
2013
basically i wrote: a photocell consists of an anode and a photosensitive cathode in a highly evacuated glass tube. When light of a frequency higher than the cathode's threshold frequency strikes the cathode it emits free electrons by the photoelectric effect. The electrons are accelerated as a focussed beam towards the positive anode due to a applied potential difference, this initiates a photocurrent. The current can be amplified to do work in an external circuit; e.g. power a lamp.

Isnt photocells easier than solar cells?
Much easier
 

panda15

Alligator Navigator
Joined
Feb 22, 2012
Messages
675
Gender
Male
HSC
2013
Yeah heaps disappointed
That there was no projectile
This! I just realised this!
What the hell? Why are we the year that gets no projectiles? They're the easiest marks in the paper...
 

omgiloverice

Member
Joined
May 11, 2012
Messages
160
Gender
Male
HSC
2013
bad luck for me I only realised that photocells aren't solar cells at the very last 30 seconds... I remember the hsc exams once made a mistake on photocells and solar as well. But I can't seem to find the question...
 

Web Addict

Member
Joined
Oct 19, 2012
Messages
462
Gender
Male
HSC
2013
Actually, pretty awks for your PhD teacher when he is incorrect.

Have a look at where that the dot point concerning photocells in the syllabus.. Before semiconductors..

Hmmmmmmm....

I wouldnt be surprised if they end up accepting both
Lol. I hope the Board of Studies don't accept both. It gives me a slight chance to get a Band 6.

No projectile :mad:
Yeah, wtf? I love projectile motion. At least there were loads of calculations.
 
Last edited:

anomalousdecay

Premium Member
Joined
Jan 26, 2013
Messages
5,766
Gender
Male
HSC
2013
Photocells are pretty much the thermionic equivalent of solar cells.

It consists of 2 electrodes embedded within a vacuum tube. A large cathode covered in photosensitive material, from which photoelectrons can be emitted when subject to sunlight.
Wow. I do Age of Silicon and didn't even know that the structure is different.

Damn Jacaranda. Says that photocells can be p-n junctions.

These are photocells. PHOTOCELLB.jpg

According to Jacaranda, what you are referring to is "photo-conductive cells".

Its time for Board of studies to assess the validity of Jacaranda. That should pop-up next year in my opinion.

Otherwise, I just lost the 5 marks that I thought I smashed.

Far-out.
 
Last edited:

RealiseNothing

what is that?It is Cowpea
Joined
Jul 10, 2011
Messages
4,591
Location
Sydney
Gender
Male
HSC
2013
If jacaranda is saying that photocells includes solar cells, and many students write about solar cells because photocells don't get taught (I learnt photocells as being solar cells), then surely something would have to be done?
 

anomalousdecay

Premium Member
Joined
Jan 26, 2013
Messages
5,766
Gender
Male
HSC
2013
If jacaranda is saying that photocells includes solar cells, and many students write about solar cells because photocells don't get taught (I learnt photocells as being solar cells), then surely something would have to be done?
2014 HSC 3 marks:

"Explain how you assessed the validity of data from textbooks."

Do you have Jacaranda? Have a quick look at it. If not, pm me.

Ironically, Jacaranda is my source for Age of Silicon and LDRs are shown as pn junctions. Look at the picture above.

Honestly, if the person who wrote about photocells wrote age of silicon, then we can can get the marks.

Anyway, even if we did stuff up, we would still get two marks for addressing that dot-point of the syllabus maybe?
 

Users Who Are Viewing This Thread (Users: 0, Guests: 2)

Top