HSC Physics Marathon 2013-2015 Archive (3 Viewers)

[InteGrand]

re: HSC Physics Marathon Archive

do we take into account the mass of the moon or Earth?

 

[leehuan]

re: HSC Physics Marathon Archive

I need to know information about this dot point so I'm going to ask this question and let someone else mark it. (Please)

Assess the impact of transformers on society with particular reference to the microchip and microprocessors. (5)

 

[Crisium]

re: HSC Physics Marathon Archive

I need to know information about this dot point so I'm going to ask this question and let someone else mark it. (Please)

Assess the impact of transformers on society with particular reference to the microchip and microprocessors. (5)

Ceebs answering so I'll give you information from my notes:

Microchips (Integrated Circuits):

• An assembly of electronic devices and their connections, fabricated in a single unit/chip, which is designed to carry out specific tasks as they would if they were made individually by connecting wires.

• It is very small (i.e. 1.5 cm2), but contains numerous transistors and diodes, and their interconnections to carry out a very complex operation.

• One type of transistor used in integrated circuits are Metal Oxide Semiconductor Field Effect Transistors (MOSFET), which are voltage-controlled devices. They are used in digital circuits to switch electric signals on and off, thus operating at switches. They are commonly found in digital devices such as the computer.

Microprocessors:

• A type of microchip that contains enough complicated electronic devices and their connections to perform arithmetic, logic and control operations.

• An example of a microprocessor is the central processing unit (CPU) of a computer. Since it integrates more devices into a single chip, it is capable of a more powerful function.

• Since the semiconductor devices are closer together on the chip, the transmission of signals between the devices becomes more efficient due to the smaller operating distance between the devices. Furthermore, this small distance results in less resistance to electric signals, thus reducing heat loss, meaning that the devices become more power efficient, and the requirement for heat removal is also reduced.

• The manufacturing costs of microchips are proportional to the area of the chip, meaning that the addition of more devices to a single chip, results in an increase in complexity but does not raise the total cost of production. Mass production due to higher demand further reduces the costs of manufacturing the microprocessors.

Evaluation of Impact:

• The applications of microchips and microprocessors reduce the problems of variable resistance in wiring and soldering components, and extends to many forms of electronic devices, such as medical diagnosis applications, biotechnology and telecommunications. However, this misuse of these devices can severely affect society in a detrimental manner.

• The further development of microprocessors enables more powerful and smaller computers to be made. Computers are essential in our daily lives and are used in business and industries to better cater for the needs of society. Furthermore, through the internet, society is capable of accessing virtually all the information on the planet.

• The development of microprocessors also leads to the invention of intelligent terminals and robots, which are employed in specific areas to replace human labour in performing a task that would otherwise involve repetitive heavy labour or the potential for dangerous situations. Consequently, this task can be carried out quickly, efficiently and with little supervision, in places such as the automobile industry.

• It has resulted in high unemployment rates, as the robotics have made the workers redundant by performing their tasks to a level to quality unmatched by human labour.

• There has been a reduction in face-to-face social interaction for many users of computers and other communication mediums.

• The use of solid state devices by the military raises ethical issues concerning pacifists, as these devices allow for the manufacturing of deadly weapons.

 

[malcolm21]

re: HSC Physics Marathon Archive

Ceebs answering so I'll give you information from my notes:

Microchips (Integrated Circuits):

• An assembly of electronic devices and their connections, fabricated in a single unit/chip, which is designed to carry out specific tasks as they would if they were made individually by connecting wires.

• It is very small (i.e. 1.5 cm2), but contains numerous transistors and diodes, and their interconnections to carry out a very complex operation.

• One type of transistor used in integrated circuits are Metal Oxide Semiconductor Field Effect Transistors (MOSFET), which are voltage-controlled devices. They are used in digital circuits to switch electric signals on and off, thus operating at switches. They are commonly found in digital devices such as the computer.

Microprocessors:

• A type of microchip that contains enough complicated electronic devices and their connections to perform arithmetic, logic and control operations.

• An example of a microprocessor is the central processing unit (CPU) of a computer. Since it integrates more devices into a single chip, it is capable of a more powerful function.

• Since the semiconductor devices are closer together on the chip, the transmission of signals between the devices becomes more efficient due to the smaller operating distance between the devices. Furthermore, this small distance results in less resistance to electric signals, thus reducing heat loss, meaning that the devices become more power efficient, and the requirement for heat removal is also reduced.

• The manufacturing costs of microchips are proportional to the area of the chip, meaning that the addition of more devices to a single chip, results in an increase in complexity but does not raise the total cost of production. Mass production due to higher demand further reduces the costs of manufacturing the microprocessors.

Evaluation of Impact:

• The applications of microchips and microprocessors reduce the problems of variable resistance in wiring and soldering components, and extends to many forms of electronic devices, such as medical diagnosis applications, biotechnology and telecommunications. However, this misuse of these devices can severely affect society in a detrimental manner.

• The further development of microprocessors enables more powerful and smaller computers to be made. Computers are essential in our daily lives and are used in business and industries to better cater for the needs of society. Furthermore, through the internet, society is capable of accessing virtually all the information on the planet.

• The development of microprocessors also leads to the invention of intelligent terminals and robots, which are employed in specific areas to replace human labour in performing a task that would otherwise involve repetitive heavy labour or the potential for dangerous situations. Consequently, this task can be carried out quickly, efficiently and with little supervision, in places such as the automobile industry.

• It has resulted in high unemployment rates, as the robotics have made the workers redundant by performing their tasks to a level to quality unmatched by human labour.

• There has been a reduction in face-to-face social interaction for many users of computers and other communication mediums.

• The use of solid state devices by the military raises ethical issues concerning pacifists, as these devices allow for the manufacturing of deadly weapons.

Those impacts are legit as fuck, but how are transformers involved with transistors/ microchips cause its not in there?

 

[atargainz]

re: HSC Physics Marathon Archive

never really seen transformers paired with microchips/processors? Pretty sure he meant transistors

 

[Magnoliatient]

re: HSC Physics Marathon Archive

Those impacts are legit as fuck, but how are transformers involved with transistors/ microchips cause its not in there?

The syllabus dot point says "impact of transistors" on society with reference to microprocessors and microchips.


(But if you did get a question with transformers and microchips, which would be strange,you can talk about how transformers made the current electrical age of computers, microchips, etc possible as electricity became more efficiently transferred, and a single voltage could be changed to different voltages necessary for different devices- microchips would require much smaller voltages than 240V, and would be fried with 240V)

 

[Kaido]

re: HSC Physics Marathon Archive

How does doping affect the way a current is carried in a semiconductor? (8 marks)

Bump

If anyone can get the full 8 marks, I'll shout cookies

 

[malcolm21]

re: HSC Physics Marathon Archive

Bump

If anyone can get the full 8 marks, I'll shout cookies

wow was this actually an 8 marker? I think theres only enough info for 5 or 6 marks

 

[Kaido]

re: HSC Physics Marathon Archive

wow was this actually an 8 marker? I think theres only enough info for 5 or 6 marks

hehehe, it depends on how well you know about the donor/acceptor (Fermi) levels in the energy band theory -> and what this actually implies

 

[Drsoccerball]

re: HSC Physics Marathon Archive

wow was this actually an 8 marker? I think theres only enough info for 5 or 6 marks

Yes it is only worth this probably less... It's one of those questions kaido pulls out from his ass ahaha

 

[Mikes]

re: HSC Physics Marathon Archive

Analyse and assess Pauli's and Heisenburg's contribution to atomic theory. (7 marks)

 

[Kaido]

re: HSC Physics Marathon Archive

Yes it is only worth this probably less... It's one of those questions kaido pulls out from his ass ahaha

BAHAHAHAHAAHA, yup, it's fun doe

 

[Kaido]

re: HSC Physics Marathon Archive

Analyse and assess Pauli's and Heisenburg's contribution to atomic theory. (7 marks)

Heisenberg:
– Heisenberg founded matrix mechanics, a mathematical system which provided an explanation for the nature of small particles (e.g. electrons and protons) and their interactions.
Matrix mechanics was able to successfully predict and mathematically explain the emission spectra of many elements, not just hydrogen, and also solve the problems with Behr’s model (such as the differences in intensity between spectral lines, hyperfine structures, and the Zeeman effect).
– Heisenberg also put forward his uncertainty principle, which stated that uncertainty is an inherent property of quantum mechanics.
Δ ∙ Δ ≥ℎ(bar)/2pi
If the position of an object is known accurately, then its momentum cannot be known accurately.
This principle explains the uncertain, probabilistic nature of atomic behaviour and interactions, and has come to be a central feature of quantum theory today (e.g. Behr’s planetary model with electrons in fixed orbits was abandoned in favour of „electron clouds‟ or „orbitals‟, where an electron’s position is a statistical probability).
•Pauli:
– Pauli proposed the Pauli Exclusion Principle which states that no two electrons may exist in the same quantum state or have the same quantum numbers in an atom.
These quantum numbers are principal, angular momentum, magnetic and spin quantum numbers.
This exclusion principle could explain the electron distributions in atoms and the position of elements on the periodic table.
– Pauli also proposed the existence of the nearly massless (and often massless), neutrally charged neutrino, and in doing so, enhanced our understanding of nuclear transmutations and explained the continuous spectrum of beta decay.
– Pauli also predicted Rydberg‟s constant, and introduced the concept of spin to the electron.
Add some heavy quote to sum up this Q and satisfy the analysis. QED

 

[malcolm21]

re: HSC Physics Marathon Archive

Heisenberg:
– Heisenberg founded matrix mechanics, a mathematical system which provided an explanation for the nature of small particles (e.g. electrons and protons) and their interactions.
Matrix mechanics was able to successfully predict and mathematically explain the emission spectra of many elements, not just hydrogen, and also solve the problems with Behr’s model (such as the differences in intensity between spectral lines, hyperfine structures, and the Zeeman effect).
– Heisenberg also put forward his uncertainty principle, which stated that uncertainty is an inherent property of quantum mechanics.
Δ������ ∙ Δ������ ≥ℎ(bar)/2pi
If the position of an object is known accurately, then its momentum cannot be known accurately.
This principle explains the uncertain, probabilistic nature of atomic behaviour and interactions, and has come to be a central feature of quantum theory today (e.g. Behr’s planetary model with electrons in fixed orbits was abandoned in favour of „electron clouds‟ or „orbitals‟, where an electron’s position is a statistical probability).
•Pauli:
– Pauli proposed the Pauli Exclusion Principle which states that no two electrons may exist in the same quantum state or have the same quantum numbers in an atom.
These quantum numbers are principal, angular momentum, magnetic and spin quantum numbers.
This exclusion principle could explain the electron distributions in atoms and the position of elements on the periodic table.
– Pauli also proposed the existence of the nearly massless (and often massless), neutrally charged neutrino, and in doing so, enhanced our understanding of nuclear transmutations and explained the continuous spectrum of beta decay.
– Pauli also predicted Rydberg‟s constant, and introduced the concept of spin to the electron.
Add some heavy quote to sum up this Q and satisfy the analysis. QED

wtf is this in the syllabus??

 

[InteGrand]

re: HSC Physics Marathon Archive

wtf is this in the syllabus??

It's in the Option "Quanta to Quarks". In this Option need to know about Pauli and Heisenberg's contribution to the development of quantum theory.

If you didn't do this Option, you don't need to know about it.

 

[keepLooking]

re: HSC Physics Marathon Archive

Why does a North pole get created on the right side instead of the left?

[B is answer]

 

[atargainz]

re: HSC Physics Marathon Archive

Why does a North pole get created on the right side instead of the left?

[B is answer]

this shit tripped me out yesterday, I got a reason to why it's B but am not sure if it's legit lol. I pretty much used the right hand grip rule on the windings to determine the polarity of the magnets, then used right hand palm rule to determine whether the side of the coil was going up or down

 

[malcolm21]

re: HSC Physics Marathon Archive

Why does a North pole get created on the right side instead of the left?

[B is answer]

how do we do this question without the magnet being shown

 

[anomalousdecay]

re: HSC Physics Marathon Archive

Why does a North pole get created on the right side instead of the left?

[B is answer]

Follow the direction of the current in each case and use the right hand rule to follow the winding of the current using your fingers. Then it will become apparent that the magnetic field direction in B follows from the right to left, that is the right is a North pole and the left is a South pole.

And this too:

this shit tripped me out yesterday, I got a reason to why it's B but am not sure if it's legit lol. I pretty much used the right hand grip rule on the coils to determine the polarity of the magnets, then used right hand palm rule to determine whether the side of the coil was going up or down

 

[kawaiipotato]

re: HSC Physics Marathon Archive

Follow the direction of the current in each case and use the right hand rule to follow the winding of the current using your fingers. Then it will become apparent that the magnetic field direction in B follows from the right to left, that is the right is a North pole and the left is a South pole.

And this too:

If i used right hand grip rule for A wouldn't it mean the magnetic field goes from left to right? Allowing it to rotate clockwise too