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# Official OCR New Spec AS Level Physics: Depth in physics - 9th of May watch

1. (Original post by theguywhosaidhi)
here is a video I just watched on Uncertainty: https://www.youtube.com/watch?v=zrGSDHSOM5E
also another vid but this time on errors: https://www.youtube.com/watch?v=FL6kvz4uOHM
2. (Original post by mahmzo)
Not to be rude mate, the exam is in 4 hours and you don't know any of that? Why would you leave revision to literally the last minute?

I do know this stuff I was trying to be helpful because new spec and everything.

Good luck anywho, exams nearly over
3. (Original post by BobAhmed)
yh thats true, but with trig all u need is an angle and 1 known side, we know the angle 30 and the weight...
yeah you can do that. Use tan θ = o/a
4. (Original post by dodgewc25)
Guys in the official practice paper for depth I noticed there were a number or experiment related question where you would have to present uncertainties and systematic errors etc.... Anyone got any revision stuff for that?

So like maybe how to find uncertainties and definitions of precision/reliability/accuracy and what exactly things like random or systematic errors are just because it seems you could get quite a few marks for knowing things like this.

Any help would b emus happreciated and Good luck everyone!

There are a couple more on uncertainties too.
5. hows everyone feeling? prepared?
6. If you are given a circuit with a marked EMF of the battery, is that when you assume its a potential divider because I was told not to talk about current unless told in any of the written questions for potential dividers?
7. Also, any predictions for practical questions or anything which will come up?
8. (Original post by voltz)
If you are given a circuit with a marked EMF of the battery, is that when you assume its a potential divider because I was told not to talk about current unless told in any of the written questions for potential dividers?
Not sure what you mean by that, though it's always good to talk about current in a circuit in context.
9. (Original post by Vanilla Poison)
Not sure what you mean by that, though it's always good to talk about current in a circuit in context.
So say they asked how increase in temperature of a thermister affected the voltmeter reading on a resistor in series with it, would this be correct:

Increased temperature = lower resistance
R is proportional to V so V decreases too
Therefore the resistor gets a larger share of the voltage hence larger reading

Would you need to discuss current in this example?
10. (Original post by mm_7)
hows everyone feeling? prepared?
Feeling as prepared as I can be, only can do our best, right? Only 2 exams after physics, hurrah!
11. (Original post by voltz)
So say they asked how increase in temperature of a thermister affected the voltmeter reading on a resistor in series with it, would this be correct:

Increased temperature = lower resistance
R is proportional to V so V decreases too
Therefore the resistor gets a larger share of the voltage hence larger reading

Would you need to discuss current in this example?
The current through each component would be the same, it's only the P.D's that would change. So no you don't have to talk about current.
12. (Original post by Vanilla Poison)
The current through each component would be the same, it's only the P.D's that would change. So no you don't have to talk about current.
Thats what is confusing me, when would you mention current in such questions because I know in some past papers you have to say as total resistance increases, the current decreases etc
13. (Original post by voltz)
Thats what is confusing me, when would you mention current in such questions because I know in some past papers you have to say as total resistance increases, the current decreases etc
I get what you mean, generally those questions don't involve potential divider circuits?
14. (Original post by Vanilla Poison)
I get what you mean, generally those questions don't involve potential divider circuits?
Thats the thing, Im not even sure when to know of its a potential divider circuit - is it when you are given a fixed EMF?
15. (Original post by voltz)
Thats the thing, Im not even sure when to know of its a potential divider circuit - is it when you are given a fixed EMF?
This might help, if you have the time you can watch this.
16. hey vanilla posion,
i am in a predicament currently as i have done no revision at all because i had pro clubs whip instead of revising last night. which topics do you suggest i revise so that i can rag an e?
17. (Original post by Vanilla Poison)
This might help, if you have the time you can watch this.
So it typically has 2 resistors with a voltmeter in parallel with one? Either could be a thermister etc?
18. Mate im in the same situation except iwasnt playing pro clubs i just cb. You dont really need a levels do you
19. (Original post by voltz)
So it typically has 2 resistors with a voltmeter in parallel with one? Either could be a thermister etc?
Yep, the voltmeter can be across the fixed resistor or an LDR/Thermistor.
20. (Original post by thomanat)
Feeling as prepared as I can be, only can do our best, right? Only 2 exams after physics, hurrah!
Woo! yeah u can only try your 100%! Good Luck!

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