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AQA Physics Unit 1 PHYA1 20th May 2014 OFFICIAL

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I have only ever it ask you to draw the graph for a diode... along with filament lamp and an ohmic conductor,
Original post by hltorrance
You can work out quark structures using the data on the formula structure there is not need to memorise them :smile:


Where?
Reply 162
Original post by Reecelyons
I have only ever it ask you to draw the graph for a diode... along with filament lamp and an ohmic conductor,


what is the reversed bias drop off point? I know the forwards bias is 0.6V but I'm sure it was on a question i did and I can't remember the answer
Reply 163
Original post by samlyon
what is the reversed bias drop off point? I know the forwards bias is 0.6V but I'm sure it was on a question i did and I can't remember the answer


Is it -50V?
Original post by samlyon
what is the reversed bias drop off point? I know the forwards bias is 0.6V but I'm sure it was on a question i did and I can't remember the answer


Surely because current can only go one way with a diode in place, it just looks like the following... VI-graph-for-filament-diode.jpg
Just did a past paper.. got 59/70... Good enough?
Original post by Reecelyons
Surely because current can only go one way with a diode in place, it just looks like the following... VI-graph-for-filament-diode.jpg



Don't forget to label the 0.6 :smile:
Original post by Reecelyons
Surely because current can only go one way with a diode in place, it just looks like the following... VI-graph-for-filament-diode.jpg


diode_graph.jpg

If you extend the reverse bias, it eventually reaches a breakdown voltage where the diode's resistance suddenly drops, so a large current can flow :smile:
Original post by toddmcnugget
Does anyone have a list of the experiments we're supposed to know such as the resistivity one?

I could do with this too.

Anyone?
Reply 169
can anyone help me with potential dividers?
Reply 170
Also do we need to know Kirchhoff's circuit laws?
Original post by b.kot
can anyone help me with potential dividers?


yes yes bump this
Reply 173
Original post by Kingnig
yes yes bump this


For potential dividers the formula
Vout=Vin x R1 / (total R)

Sorry not much help aha but that's what I use most of the time


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Original post by MsFahima
Don't forget to label the 0.6 :smile:


Are you suppose to know this?What else do you need to know about potential bias because its a topic I have never come across in a diode and in the specimen it asked it and said that current flows past the ammeter when the current in a diode is very high protecting the ammeter.i have done where the current starts flowing in the direction the diode is stopping at a high negative voltage though.The specimen is so hard I got 55/70-be careful if you do it though because some of the answers are wrong.
Original post by imyimy
For potential dividers the formula
Vout=Vin x R1 / (total R)

Sorry not much help aha but that's what I use most of the time


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Potential Dividers formulas are unnecessary because the v out basically represents the voltage supplied to the component its as simple as that but AQA try to pretend its a big ew topic but its not really.
What do you guys think the big marker will be on?
Would we be expected to know what sensor potential divider circuits look like?
Totally screwed for tomorrow's paper. Should I revise throughout the night?
Original post by JM17
P=VI, P=I^2/R, P=V^2/R

Swap your P for an E and add on a t.



Original post by aLeXaNdRa08
ah, but theres no way in hell that i would have thought of that during an exam
I guess ill just have to memorise it
Thanks



Original post by JM17
Well you know Power = Energy / Time, and I'm sure this equation is in the book.

So Energy must equal power times time, so swap E and P and add on t.


P=IV I=Q/t V=W/Q (all given on data sheet)

P=(Q/t)*(W/Q)=W/t=E/t (work is just energy)

Goodluck guys I had this exam last year hope you all do ok!

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