The Physics AS-Level Thread

I have realised how you do this now-the battery's resistance must act in series and I think this is because if you see this on proper diagrams the battery's virtual circuit is a separate bunch compared to the other resistors and the other two in parallel giving the total resistance as 8 +1/(1/8+1/8)=8+1/(2/8)=8+4+12 so I=1 because V=IR I=V/R=12/12=1 the current flowing though the battery is 1 and P=I^2R=1^2*8=8 watts and the current flowing through each of the other resistors is 1/2=0.5 so P=I^2R=0.5^2*8=0.25*8=2 watts for both of them.

Ok I need help agaiin guys, I really appreciate the help I get.

I was attempting some questions and I couldnt figure out how to do it after leaving it and coming back to it. The question is the following:

Two 8(Ohm) resistors and a battery of emf 12.0v and internal resistance 8 (Ohm) are connected in series with each othe. Sketch the circuit diagram and calculate

i) The power delivered to each external resistor

ii) The power wasted due to internal resistance
(These questions I get is part b I dont understand) Read on

b) The two 8 (Ohm) resistors in a are reconnected in parallel with each other then connected to the same battery. Sketch the circuit diagram and calculate

i) The power delivered to each external resistor

ii) The power wasted to internal resistance

I got the following as what I thought the circuit would look like

(This is the question I dont understand part bi() and I havent attempted bii) yet

Thanks for this, I understand what you're doing but why cant you work out the Current for the 2 parallel resistors using the formula I=V/R

I understand that since the battery produces 1A of current current is different in parallel and since the resistance is the same for both resistors the current will split equally. But say they weren't the same how would you work out the current because I=V/R wouldnt work

I = 12/8

for the resistor and that would give u 1.5 for the current through the resistor which is clearly wrong

Hey, does anyone know any good resources for chapter 2 quarks and leptons. Im finding it a bit confusing.


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[video="youtube;U0kXkWXSXRA"]https://www.youtube.com/watch?v=U0kXkWXSXRA[/video]

I was wondering if anyone could help here - i got the right answer but am sure my method is incorrect...

'Calculate the resistance of a heating element designed to operate at 60W and 12V'.

Using V=W/Q, i got Q=5C.

Using P = I^2(R); 60 = 25(R) gives R = 2.4Ohms, the right answer.



However, i have used Q (Charge) instead of I (Current) but still still got the right answer, even though Q = I*t??????

Any help appreciated!

Hello all it's great this thread exists thank you!

(...) What about yourself?

I like so much kinds of physics, but nuclear and quantum physics most of all. Mechanics is interesting too.

Apparently physics gets much harder next year :s


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Awesome. Have u just started AS too? (...)

It's all relative

If I don't have started AS physics, I would not be here. At the moment I'm studying more details of quantum and nuclear physics.

very good


If I hadn't started AS Physics*

How old are you?

As you can take from my profile, I'm 28. No one is too old to learn physics.

I've been told the only leptons which are stable are electrons and their neutrinos.
So thats electrons and electron neutrinos right?
How do the other leptons become stable if they don't decay?/are fundamental? Why are they not 'stable'?


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I've been told the only leptons which are stable are electrons and their neutrinos.
So thats electrons and electron neutrinos right?
How do the other leptons become stable if they don't decay?/are fundamental? Why are they not 'stable'?


Posted from TSR Mobile