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HSC Physics Predictions / Thoughts (1 Viewer)

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There was drag and drop for longer responses and you only type in calculation questions. You could look through the exam, but time is better spent doing questions on pen and paper.
do u think the questions on it were any good?
 

Fabrizio

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There was drag and drop for longer responses and you only type in calculation questions. You could look through the exam, but time is better spent doing questions on pen and paper.
yeah i just quit it when i realised it was like that
 
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yeah i just quit it when i realised it was like that
The questions were okay, so maybe its worth looking over if you want. You just have to make an account before today ends i think
im browsing thru it now, some of these questions go rly in depth (at least for what our physics class has been doing). the calculations seem mostly fine but to you or anyone else do some of those drag-drop questions seem really quite in-depth?
 

Speed’o’sound Sonic

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We have got to beat the HSC Chemistry Thoughts/Predictions in number of views and replies because we by far are the superior science. So far we have more replies but less views. Come on guys you can do it!

Anyway how are you all feeling for the exam?
Feeling positive at the moment. Just looking through last years paper hoping it is as similar as possible honestly haha.
Looking forward to any extended responses on Mod 7 as I feel that is the module I have greatest depth of knowledge in.
Also looking forward to some simple Mod 5 calculations
The Mod 8 theory is my main problem at the moment, but luckily I have a few days to really learn it.
 
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OH ALSO ive noticed that that mod 7+8 seem to be the main ones in extended response w/ 5 and 6 being more problem solving. can anyone verify this?
 

shashysha

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OH ALSO ive noticed that that mod 7+8 seem to be the main ones in extended response w/ 5 and 6 being more problem solving. can anyone verify this?
yeah cause most of mod 7 + 8 is theory whereas 5/6 focuses more on calculations, although they can still ask on lenz law or satellites as 3-5 markers i reckon
 

Speed’o’sound Sonic

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I literally cannot cram mod 8 with all the H-R diagram, solar system, supergiant, Snow White and seven dwarfs bla bla blo blo. Anyone has any suggestions?
Do you have any other exams? If not I’d just write up some concise notes, read through textbook and answer a lot of practice questions. Then write out knowledge without looking and mark your own work etc.
I got the whole week so we chilling 😂
 

Marshall17

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Hi guys, I have a question. If certain chemicals energy is required to produce voltage in the circuit, but due to back emf the actual voltage is less than the applied voltage, is energy being lost?
 

Speed’o’sound Sonic

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Hi guys, I have a question. If certain chemicals energy is required to produce voltage in the circuit, but due to back emf the actual voltage is less than the applied voltage, is energy being lost?
Back emf can never be greater than applied voltage, as far as I know.
 

Speed’o’sound Sonic

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Yes what i mean is the actual voltage becomes V applied-back emf, so net V decreases, so does that mean a higher energy than usual is required to maintain the net voltage?
In a motor there is no need to maintain net voltage as it will reach its efficient rotating speed and stay there, where there is an equilibrium between back EMF and applied voltage, and current is minimised
 

Marshall17

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In a motor there is no need to maintain net voltage as it will reach its efficient rotating speed and stay there, where there is an equilibrium between back EMF and applied voltage, and current is minimised
Yes, but the supply voltage is still the same. But some of the potential difference is "lost"due to back emf. My confusion is, starting with the assumption (possibly incorrect) that certain amount of chemical energy in battery in required to maintain the source voltage difference, and the actual potential difference is less, where did that extra energy go?
 

Speed’o’sound Sonic

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Yes, but the supply voltage is still the same. But some of the potential difference is "lost"due to back emf. My confusion is, starting with the assumption (possibly incorrect) that certain amount of chemical energy in battery in required to maintain the source voltage difference, and the actual potential difference is less, where did that extra energy go?
When observing conservation of energy it’s often useful to think of P=VI so if net voltage drops, one would assume that current must increase to counteract this change. We don’t really tend to discuss batteries as a source of chemical energy though, it’s not a part of the syllabus
 

Fabrizio

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Yes, but the supply voltage is still the same. But some of the potential difference is "lost"due to back emf. My confusion is, starting with the assumption (possibly incorrect) that certain amount of chemical energy in battery in required to maintain the source voltage difference, and the actual potential difference is less, where did that extra energy go?
You're over complicating the shit out of it. All you need to know is how back EMF restricts the operation of motor (reduces current ans thus magnitude of motor effect) and why/how its created (magnetic flux changes at an increasing rate as the motor spins faster inducing more back emf and conservation of energy)
 

Speed’o’sound Sonic

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You're over complicating the shit out of it. All you need to know is how back EMF restricts the operation of motor (reduces current ans thus magnitude of motor effect) and why/how its created (magnetic flux changes at an increasing rate as the motor spins faster inducing more back emf and conservation of energy)
Factsssss
 
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You're over complicating the shit out of it. All you need to know is how back EMF restricts the operation of motor (reduces current ans thus magnitude of motor effect) and why/how its created (magnetic flux changes at an increasing rate as the motor spins faster inducing more back emf and conservation of energy)
ur right, i find the more u look into shit in this course the more convoluted and contradictory things can get. its one of the few courses in which a deep understanding of the content doesnt *always* seem to be a massive drawcard
 

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