EST HSC Exam (2 Viewers)

[DunnyBasher]

How'd we all go?

I found it to be quite straightforward...few things I bullshitted my way through, but otherwise a good exam.

 

[Yamaelf]

well taht was harder than our trials. i dont think i did great

 

[Envoytheguy]

The majority of it was OK. I BSed my way through, and my two drawings were a bit dodgy lol
What did you guys get for the Height of the question about the airship powered by a DC? 2400? or 1900 something?

 

[E-Dog]

Oh man - Trickier than I anticipated. But overall alright. I had to fight down the lols at that question about how much force is the cable holding in KN.... "duhhhhhhhh...."

 

[DunnyBasher]

The majority of it was OK. I BSed my way through, and my two drawings were a bit dodgy lol
What did you guys get for the Height of the question about the airship powered by a DC? 2400? or 1900 something?

I spent way too long on the drawings. And I got 2400m for the height.

I had to fight down the lols at that question about how much force is the cable holding in KN.... "duhhhhhhhh...."

Which was why it was only one mark

 

[DJWazly]

It was pretty straight forward except there was some tricky math 1's and a couple of hardish questions, i didnt even think of studying parts of a DC Motor

 

[gibson-166]

Oh man - Trickier than I anticipated. But overall alright. I had to fight down the lols at that question about how much force is the cable holding in KN.... "duhhhhhhhh...."

it was just the weight force of the car right? i spent ages on that question, i didnt believe that it could be that straight forward lol. then i saw the mark value

 

[Envoytheguy]

it was just the weight force of the car right? i spent ages on that question, i didnt believe that it could be that straight forward lol. then i saw the mark value

damn i got that one wrong; i realised it was weight of the car afterwards
was the max weight the cable could carry ~2000kg for the same question?

 

[iEdd]

The height would be 1200m if you simply divided voltage by current to get resistance. I think if you put 2400 you forgot to account for 2 wires.

I crossed that out and redid it, accounting for the voltage drop. The circuitry required 195V, meaning 45V could be dropped in the wires, allowing 4.5ohms each. The maximum height was about 225m in the end, AFAIK. Reason being that the circuitry in the airship draws 5A - that means its internal resistance is this, NOT the resistance of the long wires. If you didn't have to account for voltage drop, why would they quote the 195V figure?

Edit: Pretty sure these are correct for multiple choice. Appreciate input:
1. D
2. A
3. B
4. A
5. C
6. D
7. B
8. D
9. D
10. C

 

[crestor]

didnt like it, but some of the stuff was so good because it was straight from the physics course and with that test yesterday it was all fresh

Hate drawing questions so those two pissed me off but it was a straight forward test if you studied I thought, except for the fact i didnt do alot of study :|

what did people get for the multi choice question about the rod if it had half the density of water? I had no idea

 

[iEdd]

Ah yeah, the drawings were crap. My pictorial was kinda "eh it'll do" job.

I think the water one was half-length. Reason being is the rod is half the density of water, so requires twice the volume of water to displace that volume. Hence, 50mm for a 100mm rod.

 

[crestor]

Ah yeah, the drawings were crap. My pictorial was kinda "eh it'll do" job.

I think the water one was half-length. Reason being is the rod is half the density of water, so requires twice the volume of water to displace that volume. Hence, 50mm for a 100mm rod.

yes, my logic prevailed, all be it ill lose at least 6 makrs for drawings

 

[robotguy002]

The height would be 1200m if you simply divided voltage by current to get resistance. I think if you put 2400 you forgot to account for 2 wires.

I crossed that out and redid it, accounting for the voltage drop. The circuitry required 195V, meaning 45V could be dropped in the wires, allowing 4.5ohms each. The maximum height was about 225m in the end, AFAIK. Reason being that the circuitry in the airship draws 5A - that means its internal resistance is this, NOT the resistance of the long wires. If you didn't have to account for voltage drop, why would they quote the 195V figure?

Edit: Pretty sure these are correct for multiple choice. Appreciate input:
1. D
2. A
3. B
4. A
5. C
6. D
7. B
8. D
9. D
10. C

I got the same for the multiple choice. And I did the same for the voltage drop, but wasn't entirely sure about it... makes more sense now though.

 

[iEdd]

Awesome. Also another way to think of it is that if you account for the wires only, then when you reverse the process (V=IR), the whole 240V is dropped across the wires, meaning nothing else can be in the circuit. So yeah I think we did it right.

 

[9deuce]

Mechanics pissed me off, and I left 2 questions I think, as I had to do that 5 mark drawing.

Mods, why is there no Engineering Studies forum in the Exam Thoughs?

 

[iEdd]

Yet there is an agriculture one. They obviously knew what exams were on today, probably just hate engineers.

 

[Aaron.Judd]

Can you psot up the paper?

 

[iEdd]

I don't have it. You can only keep the multiple choice and I already posted my answers to that.

 

[E-Dog]

Awesome. Also another way to think of it is that if you account for the wires only, then when you reverse the process (V=IR), the whole 240V is dropped across the wires, meaning nothing else can be in the circuit. So yeah I think we did it right.

Yeah but shouldn't you not use 240v because it only draws 195v not 240?

 

[iEdd]

Exactly... So you cannot have a voltage drop of anymore than 45V in the wires.

The total voltage is 240V in the circuit, dropped 45V across the wires and 195V in the circuitry.