Hi again Science shorts, I just wanted to ask: - For a question such as 21 (with a P-i graph), would you be expected to know the graph shapes or always work them out based on what knowledge you have? - And also, Is Science Chinos your arch nemesis? Thanks
for question 20 at 22:10 why do you add the voltages together instead of subtracting them since its asking for the potential difference i would assume you have to subtract them?
with percentage uncertainties if it says to square it just means add it twice so for example 3 squared in percentage uncertainty means 3+3 so 4 squared means 4+4 which equals to 8 for percentage uncertainties you always just add even if it looks like you're meant to divide or square etc . I hope that makes sense sorry Im a student too so my explanation may not be that good
i think its just an example to say because the current is passing through a resistence of 10 ohms every resistor , if you take two points between the two branches , you will get 0v measured
I know this video is old but I'm confused by question 16 (17:00). Wouldn't the resistor at the bottom also be in parallel? Why can you just add it onto 3/r?
It's not in parallel. If you look at the battery, when you go from positive end to the negative end, you have to go through that bottom resistor. It's in series because it forms a closed loop with every battery. Tbh it's kind of hard to explain but it just is, if you can't wrap your head around it do practice questions until you understand it intuitively.
4:38 Q5 the answer should be B, no? A=pi×radius² not diameter. you need to half the 4.0%, you would then get an answer of 9.5% overall. 13.5% must be a throw off answer for those who don't half the 4.0%.
@@ScienceShorts hi for Q21 im a bit confused on what you're saying. "to increase I you need to increase V" like it makes logical sense in my head but I don't understand why you discount P=IV. in an exam i would automatically go to P=IV and get stuck lol. can you explain a little further? i think i understand why u need a constant in there. is it possible to use P=IV & if yes how would you do that? im tired and off my meds sorry lol
You just need to know that voltmeters have infinitely high resistance (and ammeters have near enough 0 resistance). And because the voltmeter is effectively in series now the switch is open, the very high resistance means that no current can then flow through it.
And if you can't remember that just think ammeters are always in series so must have 0 resistance (or no charge could ever flow through the circuit) and voltmeters are (meant to be) in parallel, so must have infinite resistance so that no charge flows through the branch the voltmeter is on (all goes through the component(s) it is measuring)
do you think you'd be able to cover long aqa a level physics questions anytime soon? your vids are a big help!
He does full past papers mate so just look at questions by topic on those full past paper videos
@@anthonywilliams7777 its okay im in university now lol
what did u get
@@luddy20
@@luddy20 I'm not 😔
@@CartmanProductions681 push through bro A levels is the worst but it gets sm better from there
Thank you so much! This has been a massive helping understanding how to actually do these questions. I hope you keep making these.
some lovely explinations u saved my life i was about to drop alevel physics but after ur vidoes and explinations i changed my mind thank uuuuuuuuuuuu
Hi again Science shorts, I just wanted to ask:
- For a question such as 21 (with a P-i graph), would you be expected to know the graph shapes or always work them out based on what knowledge you have?
- And also, Is Science Chinos your arch nemesis?
Thanks
Nice video, I like how you tell which topic covers that specific question.
Hey just wanna tell you love ur vids really get to learn a lot never give up
Thank you for going through these, cleared up a lot of misunderstandings.
Please could you start doing worked solutions for the actual questions too. These videos are really helpful so thank you
for question 20 at 22:10 why do you add the voltages together instead of subtracting them since its asking for the potential difference i would assume you have to subtract them?
total pd in series is added together- it’s asking for difference between P and the earth not between the two resistors
6:31 nice comedic relief in the midst of a brain wrenching😂
q22 is a rollercoaster
Q5. 4^2 is not 8, its 16, therefore the answer is 21.5?
with percentage uncertainties if it says to square it just means add it twice so for example 3 squared in percentage uncertainty means 3+3 so 4 squared means 4+4 which equals to 8 for percentage uncertainties you always just add
even if it looks like you're meant to divide or square etc . I hope that makes sense sorry Im a student too so my explanation may not be that good
Thanks.
14:53 why does it decrease by 2v?
idk either
i think its just an example to say because the current is passing through a resistence of 10 ohms every resistor , if you take two points between the two branches , you will get 0v measured
Great video- was really helpful
fantastic thanks, day before paper 1
I know this video is old but I'm confused by question 16 (17:00). Wouldn't the resistor at the bottom also be in parallel? Why can you just add it onto 3/r?
It's not in parallel. If you look at the battery, when you go from positive end to the negative end, you have to go through that bottom resistor. It's in series because it forms a closed loop with every battery. Tbh it's kind of hard to explain but it just is, if you can't wrap your head around it do practice questions until you understand it intuitively.
@@pedrofile9661 Oh I see now. Thanks, that makes a lot of sense.
19:45 all that for one mark is daylight robbery
4:38 Q5 the answer should be B, no?
A=pi×radius² not diameter. you need to half the 4.0%, you would then get an answer of 9.5% overall. 13.5% must be a throw off answer for those who don't half the 4.0%.
That's not how uncertainties work.
Uncertainty doesn't decrease just because you halve the value.
@@ScienceShorts hi for Q21 im a bit confused on what you're saying. "to increase I you need to increase V" like it makes logical sense in my head but I don't understand why you discount P=IV. in an exam i would automatically go to P=IV and get stuck lol. can you explain a little further? i think i understand why u need a constant in there. is it possible to use P=IV & if yes how would you do that? im tired and off my meds sorry lol
Super helpful thanks!
Hi for question 14 how do we know we are losing 2v every time?
Yh that’s what I’m confused about
huge help, keep it up.
8:00 why is there no current. And how did u infer that the voltmeter has such high resistance?
You just need to know that voltmeters have infinitely high resistance (and ammeters have near enough 0 resistance). And because the voltmeter is effectively in series now the switch is open, the very high resistance means that no current can then flow through it.
And if you can't remember that just think ammeters are always in series so must have 0 resistance (or no charge could ever flow through the circuit) and voltmeters are (meant to be) in parallel, so must have infinite resistance so that no charge flows through the branch the voltmeter is on (all goes through the component(s) it is measuring)
worked solutions for the questions pls
PDF?plz
u the man
7:13 how did you know that those two together make 20 ohms?
Two identical resistors in parallel = half one of them.
Use the equation to prove it to yourself!
can someone please explain why v/3=2I at 19:49
V=IR and R = 2