27 Wtf (1 Viewer)

[dolbinau]

What were the questions to 27? I feel like I'm missing something. Did we have to draw a graph?

 

[independantz]

IF 27 is the last q, then they gave us a graph and we had to do stuff with it.

 

[alez]

27 was the chromium wire one?
if so, we had to plot the second wire on the graph (was so close to missing that), work out which one was pure and which was the alloy, and then account for the inconsistent value

 

[cultured]

what was it? i can't remember. the last onnneee... ahhh. brain. is dead.

 

[dolbinau]

Was that just part of the 2 mark question about which one is pure, Alez?

2 marks to find resistance, 2 marks for Pure one, 1 mark for Outlier - It's out of 6. What am I missing?

 

[cultured]

you just calculate the resistance off the graph or say that V=IR therefore I=(1/R)V, so the one with the larger gradient had a smaller resistance.

 

[dwarven]

the 2 marks for plotting the other wire?

 

[cookiemonsterz]

oooh that reminds me. the very last part of q 27. Why is one of the points off the line. I put because the wire is not a perfect ohmic conductor and therefore wont conform perfectly to v=IR. thoughts?

 

[Kearnzo]

questions 27 was the last question in section 1.

It talked about how two students had tried to determine which of two wires was pure chromium and which one was chromium alloyed with nickel.

We were given a table of values comparing the amps with voltage supplied with the currents the flowed for both the wires.

They had already drawn a graph with wire x's voltage compared to the current.

We then had to draw then same thing for wire y.

Then it asked what the resistance was for wire y. Did that 2 ohm thingo have anything to do with the calculations? I forget year 11.

Then they asked the physical reason for the outlier.

 

[jcurry]

i said due to the increased voltage it heated up and incresed the resistance and hence got a lower than expected current
not sure if it was right though

 

[runnable]

I said physical reason was that the wire heated up due to previous experimentations, hence higher resistance.

 

[dolbinau]

Fuck. I missed the part about y, GUH. Where was this?

 

[Pwnage101]

oooh that reminds me. the very last part of q 27. Why is one of the points off the line. I put because the wire is not a perfect ohmic conductor and therefore wont conform perfectly to v=IR. thoughts?

lol yeh im pretty sure i got that wrong, i changed my asnwer from that to 'the ammeter goes up to 2.50 only' LMAO i cant stop laughing at how stoopid my asnwer was, oh well, it fit pretty well at the time ----> 1 mark

and did we have to subtract 2 ohms from our answers (ie inverso fo the gradient of graph) caus ethere was a 2 ohm resistor in teh circuit??

 

[runnable]

i said due to the increased voltage it heated up and incresed the resistance and hence got a lower than expected current
not sure if it was right though

hi 5

 

[runnable]

Apparently we needed to subtract the 2 ohms. I didnt see that, damn.

 

[Batesy27]

which one was the pure chronium? i put wire x because it had less resistance and adding impurities increased resistance but not sure

 

[alez]

lol it had the first bit right up the top
i almost missed it too

 

[alez]

which one was the pure chronium? i put wire x because it had less resistance and adding impurities increased resistance but not sure

had x as well cause it had lower resistance due to uniform structure

 

[dolbinau]

That sucks SO Much

So the thing must be

2 marks for graph

1 mark for resistance

2 marks for which one is pure

1 for for outlier

THAT makes sense.

Damn. Lost 3 marks in that question...if I drew the graph the pure one would have made more sense (got it right but wrong reason).

Now, regarding resistance. Did we have to find it for X or Y? I don't think we had to subtract 2 ohms because the voltage reading was within the circuit but if so that's another mark lost. GUH

 

[jcurry]

hi 5

yaya