HSC Physics Question Thread

[jakesilove]

Hey could I get a hand with question 9 from the 2015 paper? Sorry can't upload the photo but here's the link https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-physics.pdf

For questions like this, always look to the formula sheet. You'll find that



You can use that to find the force on R due to Q. The force will be REPULSIVE. Use the formula again to find the force on R due to P. The force will be ATTRACTIVE. Because R due to Q will be greater than R due to P, there will be an overall repulsive force. Subtract the two values, and the force is to the right!

[imtrying]

Question 24c) from the 2015 HSC has got me very confused, could I get a hand with that one please?
Also thank you so much
https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-physics.pdf

[Brenda0708]

Hi, I'm a bit confused with the direction of the magnetic field in this question. If we use the RHP rule then shouldn't the MF be out of the page, not into the page? (HSC 2002 q25c)

[pels]

I have a question here. I've never heard of Type 1 and 2 Superconductors, and I don't recall them being in the syllabus, but do we need to know the concept?

Also, here is the question:

"Discuss the effect of temperature on the conducting properties of both Type I and Type II superconductors with reference to the BCS Theory"

[Cindy2k16]

Hi whats the order of all these events in the reconceptualisation of light like: MM experiment, Special theory of relativity, Maxwell, Hertz, Planck and Einstein's explanation of the photoelectric effect? Should we know it? I only know the order in the separate topics of Space and I2I but not how they overlap.
TIA

[Cindy2k16]

Hi another question- when talking about the BCS theory, is something along the lines of the following sufficient?:
1. electron creates lattice distortion, creating an area of greater positive charge density
2. another electron being attracted to the area of greater positive charge density and thus being indirectly attracted to the electron that created the positive charge dense area
3. Cooper pair is formed and moves through the lattice unobstructed by the lattice and rather, facilitated by it with no energy loss.

Or should we be also talking about electron-phonon exchanges?

[Cindy2k16]

I have a question here. I've never heard of Type 1 and 2 Superconductors, and I don't recall them being in the syllabus, but do we need to know the concept?

Also, here is the question:

"Discuss the effect of temperature on the conducting properties of both Type I and Type II superconductors with reference to the BCS Theory"

Hi Type 1 and 2 semiconductors fall under the syllabus dot point "Process information to identify some of the metals, metal alloys and compounds that have been identified as exhibiting the property of superconductivity and their critical temperatures"
Theres not much you need to know about them though I think:
Type 1: elements (metals). Have very low critical temperatures. Have a sharp transition from normal to superconductivity once critical temperature is reached (not sure if you even need to know this bit)
Type 2: metal alloys/compounds (ceramics). Higher critical temperatures than Type 1 .more gradual transition from normal to superconductivity.

I am not sure if you are required to be able to recall the names of type 1 and 2 superconductors though. I guess if worse comes to worse you can always just recall mercury as a Type 1.
Hope this helps

[JemexR]

Yeah, that was a fucking terrible diagram hey! Basically, you need to use the right hand rule to figure out the direction of the electromagnets (follow the current around; will there be a north pole on the right, or the left?). Then, establish the direction of the current flow (again, just follow the positive to the negative, as that will be the direction of current). Then, compare these two things (ie. draw where N and S are, and the direction of current flow), and figure which one will turn as desired! Does that make sense?

I did that and it seems I've understood the diagram horribly since I'm coming up with thwo as the exact same T.T

[JemexR]

I have a question here. I've never heard of Type 1 and 2 Superconductors, and I don't recall them being in the syllabus, but do we need to know the concept?

Also, here is the question:

"Discuss the effect of temperature on the conducting properties of both Type I and Type II superconductors with reference to the BCS Theory"

Just supporting what Cindy said, but type 2 superconductors don't necessarily hit superconductivity -> in exchange of achieving "superconductivity" at higher temperatures, the substance will exhibit near-superconductivity, but not 0 resistance.

[JemexR]

When calculating torque, does the A stand for the total area or just the half (as in, if it is just one side of the coil; from the edge to the axis)?

[Cindy2k16]

When calculating torque, does the A stand for the total area or just the half (as in, if it is just one side of the coil; from the edge to the axis)?

The total area of the coil

[jakesilove]

Question 24c) from the 2015 HSC has got me very confused, could I get a hand with that one please?
Also thank you so much
https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-physics.pdf

Hey! This is a seriously tough question, and actually requires you to analyse the motion using projectile formulas! You know the constant accelerating force from b). If anything undergoes a constant acceleration in a single direction, and it's travelling in that direction, it's as though a particle is being acted on by gravity.



Find the acceleration, and then use



to solve for v! We know the electron starts at rest (u=0), we know the acceleration, and we know the distance (delta y)

[jakesilove]

(Image removed from quote.)
Hi, I'm a bit confused with the direction of the magnetic field in this question. If we use the RHP rule then shouldn't the MF be out of the page, not into the page? (HSC 2002 q25c)

So, if the negative plate is the bottom one, it will repel the electrons. We therefore need to ATTRACT the electrons downwards, to cancel out the force. Remember that electrons move in the opposite direction to current, so we stick our thumb to the left, our palm down, and get a MF into the page

[jakesilove]

I have a question here. I've never heard of Type 1 and 2 Superconductors, and I don't recall them being in the syllabus, but do we need to know the concept?

Also, here is the question:

"Discuss the effect of temperature on the conducting properties of both Type I and Type II superconductors with reference to the BCS Theory"

Type 1 vs Type 2 semiconductors is really not something of great importance in the HSC. They wouldn't ask a question like that anymore, so I genuinely would just ignore that whole area. Not worth your time!

[noonedoesnt]

here is a bit of a challenge i can't work out