A+ cut off?

[thatricksta]

Im guessing around 80%... (I was 1 in 3 students of my school to finish the exam... some people were still writing after the examiner told them to stop, personally I felt they should have cracked it at them or taken away their paper... it was really bad)
Anyone else got an opinion?

6 people last years exam got full marks, not sure what the cut off was for A+ but personally I smashed last years with heaps of time to spare. This year I only JUST finished, made some silly mistakes... but overall feel OK after looking at solutions


solutions:
http://www.itute.com/board/viewtopic.php?f=6&t=2414

has m&s detailed study (I did relativity, so am still nervous about my result)

Overall the detailed studies seemed pretty messed up. Extremely harder than other years

[tony3272]

Same thing with me... I hope it's around 80% or I'm going to cry.

[woolworth]

where did u see the solutions at?

[forumguy]

YEAH RIGHT. If anything it'll be more like 80/90 realistically.

[thatricksta]

YEAH RIGHT. If anything it'll be more like 80/90 realistically.

Not always, in the 2009 VCAA Chemistry the A+ cut off was 78%

[woolworth]

i reckon 80-85% realistically, what was the A+ cutoff last yeear?

[Bozo]

if its 80-85% i'll be wrapped.

[thatricksta]

if its 80-85% i'll be wrapped.

+1 on this, i think i may have just breached this range... maybe..

[Bozo]

ditto

[Shark 774]

Im guessing around 80%...
Anyone else got an opinion?

6 people last years exam got full marks, not sure what the cut off was for A+ but personally I smashed last years with heaps of time to spare. This year I only JUST finished, made some silly mistakes... but overall feel OK after looking at solutions


solutions:
http://www.itute.com/board/viewtopic.php?f=6&t=2414

has m&s detailed study (I did relativity, so am still nervous about my result)

Overall the detailed studies seemed pretty messed up. Extremely harder than other years

Relativity was ridiculously hard compared to every other year!

[onur369]

What do you guys reckon out of 90 ?

[Halil]

guys, not sure which ones right but, on the itute solutions a 4500 ohm resistor is used in the circuit that was required to be drawn.

Me and a few of my friends chose a 500 ohm resistor. In the end the output voltage is still 4.5V but I dont understand why its a wrong answer.

1500 is the thermistors resistance. so --> 1500/2000=0.75      0.75x6=4.5 Volts.

ANyone else do the smae mistake?

[cranberry]

i initially used 500ohm, went back and subbed in a lower-then-1500 ohm-resistance (into voltage divider equation), as the temperature increases, (such as subbing in 1400 ohms for the thermistor) which gave a less-than 4.5v output...i cant remember the exact wording, but it asked for a min vout of 4.5v when temperature is equal to-or higher than 20 degrees of 25 degrees i cant remember the exact temp at 1500 ohms.... but yeh, with 4500 ohms resistor, with vout across it, the minimum possible vout is 4.5v and only increases as temperature increased.

[thatricksta]

guys, not sure which ones right but, on the itute solutions a 4500 ohm resistor is used in the circuit that was required to be drawn.

Me and a few of my friends chose a 500 ohm resistor. In the end the output voltage is still 4.5V but I dont understand why its a wrong answer.

1500 is the thermistors resistance. so --> 1500/2000=0.75      0.75x6=4.5 Volts.

ANyone else do the smae mistake?

As temp increases, R decreases, therefore you want the Vout over the resistor, not the thermistor.

at 25 degrees the temperature was 1500 or what ever and it takes 6-4.5v = 1.5v ( i think its a 6v battery )
the other resistor will have a voltage of 4.5v

The ratio then becomes 1.5/1500 = 4.5/x

using cross multiplication, 1.5x = 6750
x= 4500 ohms

[jinny1]

ah shit.. i used 500 ohms..

fk ill be content with an A