## AaronAndyson one year ago Derive the equivalent resistance of: Parallel Circuit. Series Circuit.

1. dan815

what do u mean

2. dan815

like actually work up to a resistance equation in circuits based off the collisions?

3. AaronAndyson

It says use Ohm's law...

4. dan815

okay phew

5. dan815

so we have V=IR atleast

6. AaronAndyson

Yes.

7. dan815

now lets see what happens across 2 series resistors first

8. dan815

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9. dan815

can we use kirchoffs law too

10. dan815

you know that if you sum up the voltages at every node around a look it has to equal 0

11. dan815

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12. dan815

now the current through resistor 1 is (v1-v2)/r1 current through resistor 2 is (v2)/r2

13. dan815

and the current through both of these have to be equal as its just 1 line of wire

14. AaronAndyson

Um.You have used KCL/KVL?

15. dan815

ya is that not allowed

16. AaronAndyson

They prefer to use Ohm's law..

17. dan815

okay

18. dan815

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19. dan815

kvl is really ohms law

20. dan815

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21. dan815

we want to find R_T such that V=i*R_T where V is the source voltage

22. dan815

which is V1 in this case

23. dan815

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24. dan815

so R_T = R1+R2

25. dan815

make sense?

26. AaronAndyson

Yep.

27. dan815

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28. dan815

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29. dan815

you want to work on this one yourself?

30. dan815

I think you get the general idea right, you want to rearrange it in a form such that its i*(some resistor exprssion)

31. AaronAndyson

I guess.

32. dan815

from the eequations above you can just solve for R_T

33. AaronAndyson

?

34. dan815

ya just manipulation its not too bad

35. dan815

good luck

36. AaronAndyson

37. dan815

thats what im saying just play around with it

38. dan815

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39. dan815

solve for RT interms of R1 and R2

40. dan815

given those ste of 4 equations

41. dan815

i dont have neuff space to write out the equations and work it in draw tool

42. dan815

just do it on paper

43. dan815

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44. dan815

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45. AaronAndyson

Thanks..

46. dan815

its missing steps

47. dan815

just put them in

48. AaronAndyson

Getting conused..

49. AaronAndyson

confused*

50. dan815

51. AaronAndyson

Everything ....

52. dan815

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53. dan815

do you get these 4 equations

54. dan815

they are from ohms law

55. dan815

technically KCL is there too but that is just a result of ohms law