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AQA physics UNIT 3 monday 30th jan 2012

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Reply 20
how the sensitivity of the equipment could be increased what did you put??
Reply 21
oh god - they best lower the grade boundaries!
Original post by FiGuev
what did you get for the least number of coils needed -- something like that? first i put 30 then last second changed it to 21


I was gonna do that but then there was no specific observation for this value so instead I said 30 :s-smilie: your probs right though!
Reply 23
grade boundaries best be low come march!
Original post by sandeater
how the sensitivity of the equipment could be increased what did you put??


add more turns to the coil (cus it was a generator/ motor thing)
and use a stronger/ more powerful magnet... dunno if thats right!
That exam has to be the hardest thing I've ever done. Every practice paper I've done, I get A*.. However this exam, Idk.. For the last question I got something like 240 or 600 can't remember, then very last question got like 150Nm :s-smilie: Meh, I lost about 15 marks... So hopefully boundaries are low LOL

( The P2 exam was easyish)
ive worked out that I think I got around 35 so hopefully there will be low grade boundaries!
I put 10 :frown: fml
Reply 28
how about the question with pulse A and B i wascompletey lost what did everyone put??
Reply 29
Original post by MrLegendary
add more turns to the coil (cus it was a generator/ motor thing)
and use a stronger/ more powerful magnet... dunno if thats right!


I said lighter magnet and looser spring ... :/ because that will get a sensitive results if the shakign was weaker .. not sure :s-smilie:
Reply 30
i put pulse a has a bigger boundary than pulse b :/
Reply 31
pulse a was the crack and pulse b was the back of the screw
Reply 32
:/
Reply 33
i put that the ultrasonic waves had it the inner of a dense medium (which was the crack) and came out different that the original wave that was sent through
A was the flaw, B was the end of the screw, when ultrasound hits a boundary/ interface it is partially reflected
Reply 35
Original post by MrLegendary
A was the flaw, B was the end of the screw, when ultrasound hits a boundary/ interface it is partially reflected


Thats basically what i said
Original post by FiGuev
Thats basically what i said


same i said :confused:the same thing
Reply 37
how about the moments? i put they where balanced because the turn of the anticlockwise was the same as the clockwise turn so they where balanced at equilibrium so there was no resultant force
Original post by sandeater
how about the moments? i put they where balanced because the turn of the anticlockwise was the same as the clockwise turn so they where balanced at equilibrium so there was no resultant force


Exactly what I said! :biggrin:
Reply 39
the least number of coils question i put was 21, because the voltage through the first coil was 2V and you had to use the graph to find the number of turns (which was 20, but secondary needs to be more than primary to step current up) so 21! Did anyone else put 21?

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