Physics Unit 4 Exam discussion

[krzysiek]

Yes, the average part got the best of me. I assumed, because it was not a DC generator, but rather an AC generator that it produces a voltage at it's PEAK, hence, the value I got for EMF i thought was a peak value, and we all know average means Voltage / SQRT2   so I applied this to the answer to find the 'average' - I have no idea if that is what they wanted, but for three marks, I do think they wanted something more.

I dont get why you divided it by 4? It have you the MAX flux, and it gave you the time for one quarter turn. To work out the induced emf, it is change in flux / change in time. In this case, it gave you the max flux, which is the change in flux for our purposes. The maximum EMF (peak) occurs when the flux goes from Max to 0, and this is in a one quarter turn, and it gave you the time for this.

In this sense, I believe you only use the max flux they gave you, and the time taken for one revolution. Then, from what I thought and it might be wrong, was that the value obtained was a PEAK value, as this is an AC generator not DC. So i divided the answer by the square root of 2 to get the AVG emf. I don't see where a four comes in to play ?
Hence, my spontaneous decision to divide it by 4...

[crappy]

so what was the answer to that average voltage question.

[arman]

i am sooo waiting for the solutions lol

[naved_s9994]

so what was the answer to that average voltage question.

you dont divide by 4, everything else is the same

[almostatrap]

i did 498V, i think people are over complicating it, it shouldn't matter if it is ac or dc

[TrueTears]

I would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.

Isnt TT a chick?

We think Male, but tests are inconclusive.

I am what you want me to be LOL

[avram_grant]

so what was the answer to that average voltage question.

i got  3.6x10-4

[naved_s9994]

i am sooo waiting for the solutions lol

Naa im alright..I know Ive done well   HEHE

[Over9000]

I would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.

Isnt TT a chick?

We think Male, but tests are inconclusive.

I am what you want me to be LOL

Btw, thanks TT for ur leet cheat sheet

[TrueTears]

so what was the answer to that average voltage question.

i got  3.6x10-4

Same here.

[crappy]

so what was the answer to that average voltage question.

i got  3.6x10-4

oh sigh of relief. thanks legend

[IntoTheNewWorld]

I LOVE YOU TT FOR THE EPIC CHEAT SHEET

nuff said

+9000

it was so damn awesome

[kdgamz]

I LOVE YOU TT FOR THE EPIC CHEAT SHEET

nuff said

yes yes

[m.hudson.1990]

for the explanation questions, is it fine to pretty much write word for word what was written for suggested answers on the assessors reports?

[blindman]

pretty good exam until i found out that the resistance was series and not parallel.

but i'll still get marks for working and stuff yeah?  and will i get consequential marks for the voltage difference questions because of this if everything else is right except the resistance?